Problem with Electrolux RM 4238

[Fiat Ducato]

Hi everyone firstly sorry for not been on here for such a long time. Been very busy, and with all the lockdowns, covid restrictions, busy family 4 young kids all under 10 years old.

 

This site as helped me out a great deal in the past and with the help of some top contributors, and some very clever people. I've managed to sort out some unusual problems etc.

 

Well since replacing all the old wiring with all new wiring, new fuse holders and replacing the main 12v/240v Power supply/distribution unit. Everything as been running brilliantly for over 3 years. I changed the original configuration of the fridge working on 12v when engine running connected to leisure battery to a more simply relay and connected straight to the D+ on the alternator, along with a signal wire from ignition so only works when engine is running. This as worked perfectly for years with trips around France, Spain, trips to Skegness, Great Yarmouth, Cornwall and all along the South Coast, trips up North to Lancashire.

 

Then the other day I had the fridge connected to 240v to get it nice and cold ready for a weekend trip with the kids. But not sure what on earth got into me but I started the engine with the switch on for 12v but also the 240v switch on and still connected to mains.

 

Bad burning smell, the fuse and blown apart, and noticed that the red light in the 12v switch wasn't coming on anymore.Done some checking with multi meter, power at the relay good, could be relay blown. Removed 12v switch and connected my tested leads to the 3 connectors 2 white wires and 1 brown. Power showing here with engine running 13.4v so all good . Must be switch I thought tested switch all good must be the led bulb inside the switch . Took switch apart and tested bulb no bulb lit.

 

Notice one of the plastic connectors the 12v positive one qhuch is white - weird right was burnt. So I cut it off and replaced the small section of wire from the connector block to the switch with same rated cable but red in colour for better identification and put on new connector. Put switch back on and still no red light.

 

Now I'm a little confused to exactly how this fridge is wired nit sure if from new or at some point someone as messed around with it. I've attached a couple of pics to show exactly what I'm on about. Firstly the 240v and gas both still work OK. The wiring from the relay to the connector block on top of the fridge is twin red and white. I presumed red to be live and connected that via a fuse and relay to the alternator. The white I took as earth and connected that to the earth terminal on my power fuse unit. These wires then go to a three way connector block on top of the fridge (only using 2 out of the 3) then on the other side you have 1 white wire coming from the red (live) going to the switch. Another white wire coming from the 12v in white (earth) so far I get this, not convinced with the colour choices but I get it. Now there is a brown wire also joined to the earth with the white, this goes into a grey sheath that goes behind the fridge.Again I am presuming to the 12v element. The other brown wire from this sheath goes to the switch with separate. connector. So am I missing something or is the 12v element running from the earth side forming a circuit at the switch which I'm guessing shows red light when the element is working. No red light so possibly 12v element blown.

 

I'm confused as not sure how this could work in this configuration, but it did. ??

 

As usual any comments, advice or suggestions are very welcome even if it's to tell me I'm been a numpty lol or advise me about the problems with presumptions being the mother of all **** ***.

 

Thanks

Paul

 

[Alanb]

Hi Paul,

 

You are a little confused, well so am I. Perhaps you can blame predictive text for some of it, but you could improve your phrasing in some areas.

 

I am wondering if you may have a short circuit on the fridge 12V element wirng? The fact that the 240V element was energised when you started the engine could be coincidental.

 

Your description of the connections for your added fridge relay, does not sound right. You mention connecting straight to the alternator D+, and taking a signal wire from the ignition. These two points are almost mutually exclusive. Did you mean to say that your fridge supply was taken from alternator B+? This is electrically the same as the starter battery +ve, but perhaps with a high rated fuse between the two points. In either case a suitable fuse 15A or 20A should be fitted as close as possible to the point of connection.

 

"The white I took as earth and connected that to the earth terminal on my power fuse unit." I hope that you mean the -ve terminal of your 12V distribution board. Clarification needed.

 

"Took switch apart and tested bulb no bulb lit." Do you mean that the bulb was faulty, or that it was OK.

 

I have said before that modern mutimeters are very sensitive. They can give misleading near normal readings through bad connections. A simple 12V test lamp may often give a better indication.

 

Looking at your photos, the two brown wires emerging from the grey sleeving would fit with being the connections to the 12V element. One brown wire connects to the white supply wire at the terminal block, and hence to 12V -ve (earth). The other brown wire should be connected to the load terminal of the switch. The "earth" terminal on the switch should be connected to 12V -ve. I agree with you about the bad choice of colour for continuing the red supply wire to the switch. An accident waiting to happen?

 

You are mistaken as to the function of the indicator light in the switch. All this light does is show that there ia a supply to the switch, and that the switch is in th "ON" position. The switch indicator does not indicate the condition of the element.

 

Keep an open mind. Is it possible that some of the damage was done on a previous trip, and any smell of burning was swept away? We have occasionly failed to select 12V on our fridge while travelling. As it had not been opened, the contents were OK. With the exception of high power inverters, the fridge 12V element is perhaps the largest 12V load in a motorhome. Poor connections can cause overheating and progressive deterioration. ( By chance I recently found a faulty connection behind the fridge in my PVC. From the crimping pattern it was the only one of four bullet crimps that I had not replaced when the van was new.)

 

Alan

[Fiat Ducato]

Sorry for my English and lack of clarity. Yes you are right I meant the B+ terminal on the alternator. I used an inline 15amp fuse as close to the point of connection like you said.

 

I ripped my old power supply/ charger distribution unit out as after paying for several repairs and doing a few myself it just kept playing up. Mainly to do with the connectors been too loose and intermittently working especially with regards to the 12v fridge connection and the charging side. So as it's a 1997 Fiat Ducato AutoRoller I didn't fancy paying around £500 for a new flash one. And opted for a simply 12v fuse board with everything connected through this. My leisure is connected now with new cable , fuses and a relay for charging when engine is running and I added an isolation switch to the circuit. There is also a pretty decent mains charger a victron which is fixed down and supplies the mains charging when plugged into mains at home or on site.

 

My fridge is connected directly to a 40amp 4 pin relay. Like I said power from B+ on the alternator, separate trigger wire from ignition, 12v red cable from fridge and an earth. The Earth from the fridge to earth terminal at fuse board. This setup is simple yet effective, and for over 3 years have had no issues always had cool fridge on 12v whilst driving even through Spain in over 40 degrees hear. I also added two 12v fans on a switch to help the flow of air.

 

The part you have mistaken was about the wiring colours to the switch, white colour for 12v live and white for 12v earth.

One is connected to the 12v live (red) fridge wire the other white switch wire connected to the white 12v earth fridge wire along with the brown. I changed the original white from 12v live (red) to also a red to make a clear visible difference from the other white which is earth. Not sure why this is an accident waiting to happen. Please explain. I would say 90 percent of people associate red colour wire with live. And this is exactly what it is. Yes you are correct the brown wire should be connected to the load terminal of the switch.

 

As for the led bulb out of the switch, I removed and used a 9v battery to test it and yes it lit up.

 

Sorry for the confusion.

[Alanb]

"The part you have mistaken was about the wiring colours to the switch, white colour for 12v live and white for 12v earth. "

 

I was commenting on what is shown in your photo. Two white wires going to the switch, one 12V +ve, and the other 12V -ve. Changing the +ve wire to red seems like a good idea.

 

I like the idea of a simple 12V distribution board. It embodies the KIS, or keep it simple principle.

 

The arrangement for the fridge 12V power supply seems fine, but I would have been tempted to use

D+ instead of ignition +ve.

 

Is it the inline 12V fridge fuse that was burnt?

 

If I understand correctly, the fridge should be energised with ignition ON, and fridge switch ON. No need to run engine, as fridge will draw power from the starter battery. If fridge switch not illuminated under these conditions, check both +ve and -ve supplies at switch or 3 way terminal block to a separate -ve point.

 

Alan

[Fiat Ducato]

So the plot thickens as they say. Totally bewildered and confused now after loads of testing I'm none the wiser to what the problem is. I ended up removing the fridge completely as thought it could do with a clean and general service, check. I made up so 240v testing cable and a 12v testing cable. I then proceeded to test the elements, first I removed the 240v one, plugged in the power switched it on and using a thermostat gun pointed it at the element and sure enough the temperature kept rising up to approx 150 degrees centigrade. You could really feel the heat coming off it.

I then disconnected the 240v lead and plugged in my 12v tester lead and sure enough that too got very hot very quickly. I cleaned everything up, blew out flue and burner with compressed air. I then tested all the wiring in the camper using made up connectors to my multi meter.

 

Today my new 12v 20amp rated fridge switch arrived and was thrilled convinced it must be the switch faulty

However connected it all up correctly earth to brass pin, power feed to bottom pin and switch load to middle pin. And nothing no red light. Confused I checked the wiring at point of switch at it was reading around 14v with engine running. I did a continuity test again on the brown element wires just in case of a break somewhere. Continuity was OK. Checked other wires all good. Now I'm scratching my head baffled. I have power getting to switch. Voltage indicates healthy connection to power supply via alternator. Fridge heater elements work perfectly. Not a lot to these fridges, they are fairly straightforward especially the 12v side. 2 wires red and white. Red - live, white - earth. 2 brown wires going to heater element, one connected to earth the other to live via a switch.

 

I had another little cheap round 3 pin rocker switch and when I connected that the light did work but only very dim. So there is obviously an issue. Could it be a bad earth problem. Or maybe alternator issue. Or am I missing something.

 

Please any help would be appreciated.

[Keithl]

I would start by replacing the existing earth connection with a temporary wire straight back to the relevant battery, after disconnecting the existing wire.

 

Keith.

[Fiat Ducato]

Keithl - 2022-05-19 8:34 PM

 

I would start by replacing the existing earth connection with a temporary wire straight back to the relevant battery, after disconnecting the existing wire.

 

Keith.

 

Thank you will give that a go tomorrow.

[Alanb]

Hi Paul,

 

I am pleased to read that your fridge 12V element appears to be OK.

 

I said previously "If fridge switch not illuminated under these conditions, check both +ve and -ve supplies at switch or 3 way terminal block to a separate -ve point."

 

Perhaps I should have added, "with the fridge switched ON"

 

I and it seems Keith, suspect a bad connection in the wiring. However my method is slightly different to Keith's, and may be easier to carry out as only requires an extension of the -ve meter lead. I fully endorse Keith's suggestion of using the battery -ve. In your installation, the relevant battery is the starter battery.

 

(This does raise the question as to how the -ve terminal of your 12V distribution board is connected to the chassis, or better the starter battery -ve.)

 

For the following tests, you may wish to run the engine, so as not to drain the starter battery, and to simulate normal running conditions.

 

With the fridge switched ON, measure voltages on the red and white wires at the 3 way terminal block, with meter -ve connected to starter battery -ve, or a good chassis connection.

 

If the red, +ve supply reads less than 12 V, then the problem is in the +ve supply. Alternatively if the white, -ve wire reads more than about 1.0 V, then this would suggest a fault in the negative (earth) connection.

 

Alan

 

[Fiat Ducato]

Alanb - 2022-05-19 10:35 PM

 

Hi Paul,

 

I am pleased to read that your fridge 12V element appears to be OK.

 

I said previously "If fridge switch not illuminated under these conditions, check both +ve and -ve supplies at switch or 3 way terminal block to a separate -ve point."

 

Perhaps I should have added, "with the fridge switched ON"

 

I and it seems Keith, suspect a bad connection in the wiring. However my method is slightly different to Keith's, and may be easier to carry out as only requires an extension of the -ve meter lead. I fully endorse Keith's suggestion of using the battery -ve. In your installation, the relevant battery is the starter battery.

 

(This does raise the question as to how the -ve terminal of your 12V distribution board is connected to the chassis, or better the starter battery -ve.)

 

For the following tests, you may wish to run the engine, so as not to drain the starter battery, and to simulate normal running conditions.

 

With the fridge switched ON, measure voltages on the red and white wires at the 3 way terminal block, with meter -ve connected to starter battery -ve, or a good chassis connection.

 

If the red, +ve supply reads less than 12 V, then the problem is in the +ve supply. Alternatively if the white, -ve wire reads more than about 1.0 V, then this would suggest a fault in the negative (earth) connection.

 

Alan

 

So today been out again and first tried measuring the voltage at the 3 way connector on top of the fridge red and white wires with engine running. Showing 13.63v on my multimeter which would indicate power getting from Alternator feed to fridge with engine running.

 

Then tried with some made up leads testing the voltage with multimeter at the wires from connector block to switch red and white with engine running again 13.63v. Put switch on nothing mo red light.

 

Disconnected the red and white wires from connector block and attached my made up 12v tester lead going directly to fully charged spare leisure battery and yes 12v fridge switch is showing red light. Now connected mains charger to my spare leisure battery to simulate engine running. Yes red light still working. Great I thought.

 

Disconnected the tester wires and connected the original 12v cable back to connector still no red light. Scratched my head. Removed the 12v fridge cable from connector to relay and done a continuity test to check for broken or fractured wires. No all fine.

 

Left the 12v red wire connected to the fridge connector but removed the white earth. And attached an earth wire directly to - pole on battery to rule out bad earth. No still no red light.

 

I like to think of myself as a fairly clever guy and can usually locate, diagnose and solve problems through elimination, and testing etc but this as me stumped cannot get my head around it.

 

Obviously relay is working as getting a reading of 13.63v at fridge with engine running and 0v with engine off.

[Alanb]

Paul,

 

For simplicity I have quoted your previous post in sections, and interposed my replies in brackets.

 

"So today been out again and first tried measuring the voltage at the 3 way connector on top of the fridge red and white wires with engine running. Showing 13.63v on my multimeter which would indicate power getting from Alternator feed to fridge with engine running."

 

(Yes you have measured a voltage across the fridge terminal block, but I do not think that you are getting power to the fridge. As you have not followed my suggestion, please at least repeat the above measurment with the fridge switched ON. Further 13.6V is not sufficient to fully charge the starter battery. I think that you should also measure the voltage directly across the starter battery.)

 

"Then tried with some made up leads testing the voltage with multimeter at the wires from connector block to switch red and white with engine running again 13.63v. Put switch on nothing mo red light. "

 

(This only moves the test point a few inches to the switch. The voltage with the switch ON may have revealed something, but no need to repeat at the moment.)

 

"Disconnected the red and white wires from connector block and attached my made up 12v tester lead going directly to fully charged spare leisure battery and yes 12v fridge switch is showing red light. Now connected mains charger to my spare leisure battery to simulate engine running. Yes red light still working. Great I thought."

 

(OK so you can power the fridge directly from spare battery, via switch. Hence fridge and switch seem to be OK. Problem must be in supply circuit. Cannot understand what starting the engine will do, when fridge powered from spare battery.)

 

"Disconnected the tester wires and connected the original 12v cable back to connector still no red light. Scratched my head. Removed the 12v fridge cable from connector to relay and done a continuity test to check for broken or fractured wires. No all fine."

 

( You will not find the sort of fault, that both Keith and I suspect , with a continuity test.)

 

"Left the 12v red wire connected to the fridge connector but removed the white earth. And attached an earth wire directly to - pole on battery to rule out bad earth. No still no red light."

 

(If I understand correctly, you have the normal red supply wire from your fridge relay connected at the fridge connector block. A temporary connection was made to -ve pole on which battery? It should have been to the starter battery -ve. IF so, your results suggest a high resistance in the +ve connections to the fridge. A high resistance in this context could be less than 1.0 Ohm.

 

Possible culprits are inline fuse, relay, or any other connections in the route.)

 

"I like to think of myself as a fairly clever guy and can usually locate, diagnose and solve problems through elimination, and testing etc but this as me stumped cannot get my head around it.

 

Obviously relay is working as getting a reading of 13.63v at fridge with engine running and 0v with engine off."

 

( As I have already stated 13.6V is rather low. It is a float voltage rather than full alternator output. Yes the relay is operating, and while I am sceptical when people rush to suspect relays, a high resistance contact is possible. See possible culprits above.)

 

Alan

[Fiat Ducato]

Fiat Ducato - 2022-05-20 2:08 PM

 

Alanb - 2022-05-19 10:35 PM

 

 

Alan I think either there is some communication issue or technical language differences. I am pretty sure I did exactly what you recommended just confused about the abbreviations -ve I don't know what exactly that stands for. But I'm guessing just the technical term for positive and earth terminals on 12v system.

 

You said here:

I said previously "If fridge switch not illuminated under these conditions, check both +ve and -ve supplies at switch or 3 way terminal block to a separate -ve point."

 

I'm pretty sure I answered that and done exact what you recommended here:

 

So today been out again and first tried measuring the voltage at the 3 way connector on top of the fridge red and white wires with engine running. Showing 13.63v on my multimeter which would indicate power getting from Alternator feed to fridge with engine running.

 

I then went on to say:

 

"Left the 12v red wire connected to the fridge connector but removed the white earth. And attached an earth wire directly to - pole on battery to rule out bad earth. No still no red light."

 

What I should have added was that the separate earth I attached was connected directly to the starter battery. (Of course not to the spare leisure battery as this would not make any sense). And yes fridge was switched on.

 

 

Perhaps I should have added, "with the fridge switched ON"

 

I and it seems Keith, suspect a bad connection in the wiring. However my method is slightly different to Keith's, and may be easier to carry out as only requires an extension of the -ve meter lead. I fully endorse Keith's suggestion of using the battery -ve. In your installation, the relevant battery is the starter battery.

 

This point you mention here:

(This does raise the question as to how the -ve terminal of your 12V distribution board is connected to the chassis, or better the starter battery -ve.)

 

Well my distribution fuse board is not connected to starter battery. It's for the habitation side of things and is connected via the positive cable running short distance to first an isolation switch then a believe a 30 amp fuse to the positive pole on leisure battery. The negative or earth is connected again a short distance run to negative pole on leisure battery which is earthed on the chassis. The leisure battery is fed power from starter battery which is fused either end but with a relay fitted so it only receives power from starter battery when ignition is on and engine is running. The fridge as a separate length of cable which goes from starter battery to relay but also fused at both ends with 15amp fuses. The trigger/signal wire for relay is taken from the D+ on the Alternator. The Earth for the fridge goes to my distribution fuse board (yes for leisure battery) but isn't this the same as connecting to starter earth connection. Just saves me running another long length of black cable to starter battery negative pole. Please correct me if this is a bad practice. Finally I have a separate earth from fuse board to earth connection on relay.

 

Your comment about not understanding why to have engine running when connected to spare battery. Is amisunderstanding, if you read that sentence again I said

 

"Disconnected the red and white wires from connector block and attached my made up 12v tester lead going directly to fully charged spare leisure battery and yes 12v fridge switch is showing red light. Now connected mains charger to my spare leisure battery to simulate engine running. Yes red light still working. Great I thought."

 

What I meant is by connecting the mains charger to the spare leisure battery is raised the voltage to approx the same voltage as if it was receiving charge from the alternator, thus simulating as if the fridge was running with engine running.

 

For the following tests, you may wish to run the engine, so as not to drain the starter battery, and to simulate normal running conditions.

 

With the fridge switched ON, measure voltages on the red and white wires at the 3 way terminal block, with meter -ve connected to starter battery -ve, or a good chassis connection.

 

If the red, +ve supply reads less than 12 V, then the problem is in the +ve supply. Alternatively if the white, -ve wire reads more than about 1.0 V, then this would suggest a fault in the negative (earth) connection.

 

Alan

 

So today been out again and first tried measuring the voltage at the 3 way connector on top of the fridge red and white wires with engine running. Showing 13.63v on my multimeter which would indicate power getting from Alternator feed to fridge with engine running.

 

Then tried with some made up leads testing the voltage with multimeter at the wires from connector block to switch red and white with engine running again 13.63v. Put switch on nothing mo red light.

 

Disconnected the red and white wires from connector block and attached my made up 12v tester lead going directly to fully charged spare leisure battery and yes 12v fridge switch is showing red light. Now connected mains charger to my spare leisure battery to simulate engine running. Yes red light still working. Great I thought.

 

Disconnected the tester wires and connected the original 12v cable back to connector still no red light. Scratched my head. Removed the 12v fridge cable from connector to relay and done a continuity test to check for broken or fractured wires. No all fine.

 

Left the 12v red wire connected to the fridge connector but removed the white earth. And attached an earth wire directly to - pole on battery to rule out bad earth. No still no red light.

 

I like to think of myself as a fairly clever guy and can usually locate, diagnose and solve problems through elimination, and testing etc but this as me stumped cannot get my head around it.

 

Obviously relay is working as getting a reading of 13.63v at fridge with engine running and 0v with engine off.

:->

[Alanb]

Paul,

 

Yes there does seem to be some misunderstanding. Please let us put that to one side.

 

I quote

 

"Then tried with some made up leads testing the voltage with multimeter at the wires from connector block to switch red and white with engine running again 13.63v. Put switch on nothing mo red light."

 

(You measured the voltage across the connector block with the engine running as 13.63V. Please, specifically what was the voltage at the connector block with the switch ON? I expect that it will be significantly less than 13.63V)

 

 

"Disconnected the red and white wires from connector block and attached my made up 12v tester lead going directly to fully charged spare leisure battery and yes 12v fridge switch is showing red light. Now connected mains charger to my spare leisure battery to simulate engine running. Yes red light still working. Great I thought."

 

(The above suggests that there is nothing wrong with your fridge or switch, and the problem is elsewhere.)

 

"Left the 12v red wire connected to the fridge connector but removed the white earth. And attached an earth wire directly to - pole on battery to rule out bad earth. No still no red light."

 

(This eliminates the earth or negative (-ve) connection to the fridge, therefore the problem must be in the positive (+ve) supply before the connector block.)

 

I hope that the above puts you on the right track.

 

For your information.

I asked about the earthing arrangements for your 12V distribution board for the following reason. You had stated that the fridge earth was connected to earth at the 12V distribution board. To complete the circuit a route is required to the alternator casing. You have clarified the situation there, by stating that the habitation battery negative is connected to chassis.

 

Alan

 

[Fiat Ducato]

Finally identified the problem and you were right. Problem wA with the +ve all along. And something I probably should have checked first.

 

The fuse was completely blown on the other end of the +ve cable from fridge relay to starter battery.

 

Something I didn't check as when I checked the voltage at the point with the tester lead it showed 13.63v so I presumed power was getting to that point. Same when I checked the voltage at the connector on top of the fridge it showed 13.63 with engine running so again I just presumed there was no issue.

 

Replaced fuse and wham everything sorted. But now I'm still puzzled to how power was showing on that cable with blown fuse. Idea of fuse is to break the circuit and prevent further power passing through the cable.

 

The fuses are those inline type with a waterproof cover and cable coming out on each end which I connected by soldering and then covered with glue lined heat shrinking.

 

Anyway thank you so much for taking the time to reply and all the advice you gave.

 

Very much appreciated

Paul

 

[Alanb]

Paul, and others wishing to learn,

 

Paul said in the previous post.

 

"Replaced fuse and wham everything sorted. But now I'm still puzzled to how power was showing on that cable with blown fuse. Idea of fuse is to break the circuit and prevent further power passing through the cable."

 

For an explanation, may I restate part of what I said in my first reply.

 

"I have said before that modern mutimeters are very sensitive. They can give misleading near normal readings through bad connections. A simple 12V test lamp may often give a better indication."

 

The blown fuse did prevent power getting to the fridge.

 

Alan

 

 

[Fiat Ducato]

Alanb - 2022-05-21 10:39 AM

 

Paul, and others wishing to learn,

 

Paul said in the previous post.

 

"Replaced fuse and wham everything sorted. But now I'm still puzzled to how power was showing on that cable with blown fuse. Idea of fuse is to break the circuit and prevent further power passing through the cable."

 

For an explanation, may I restate part of what I said in my first reply.

 

"I have said before that modern mutimeters are very sensitive. They can give misleading near normal readings through bad connections. A simple 12V test lamp may often give a better indication."

 

The blown fuse did prevent power getting to the fridge.

 

Alan

 

Thank you, yes you are very right. Lesson learnt.