Jump to content

Dometic RM7291 L Absorption Refrigerator


Recommended Posts

Hi All

 

I Don't know if any member can help me with a problem operating the Frig on my motorhome,

 

The problem I have is the control knob that changes the frige from gas or 12 volt or 240 volts sometimes will not work, you can sometimes fiddle with the control for a good while before it seems to click, The control knob has three settings 12v 240v or gas, there is never any resistance when operating this knob so until you see a light on you don't know if its working.

 

I think that this is just dirty contacts but I am not sure how the knob comes out will the centre just prise out or has the outer bezel also have to come out .

 

Thank You

 

Terry

Link to comment
Share on other sites

Hi Terry,

 

Looking at the parts diagram for your fridge Link it appears the control panel is the same as ours and I recently had a very similar problem with the temperature control knob.

 

To remove the knobs you simply pull them off, use a piece of soft cloth and a pair of pliers if stubborn. Behind each knob you will find a screw (227K) and if you remove these you can then remove the front panel (401) and behind it you will see the control board (523A).

I managed to release the control board and ease it forwards on the wires to replace the spindle of the temp control knob (487C). It looks as though there is a similar shaft for the selector knob (486C).

The biggest problem I had was getting the broken end of the shaft out of the variable resistor on the circuit board, I ended up drilling a very fine hole in it and threading in a very small self tapper. Best of luck if it is the same!

 

HTH,

Keith.

Link to comment
Share on other sites

.....as per the diagram here:

 

http://www.leisurespares.co.uk/files/rm7291.pdf

 

....it should pull out.

 

I know to my cost that these knobs are fairly easy to break (particularly if turned in the wrong direction :-S - splitting the shaft along its length so that it splays and does not engage firmly with the internal switch) which means that turning the knob does not always turn the switch.

 

If it is possible to turn the knob through 360 degrees I suspect you may have this problem. Try pulling the knob out to check.

 

(whilst I now have a spare, tightly winding the shaft on the knob with electricians tape (a few turns round) restored the function on mine).

Link to comment
Share on other sites

Hi Keithl & Robinhood

 

Thank you for your help with my Fridge problem, I will strip mine down tomorrow and see what I can do.

 

I don't know why they have not put a system on with the shaft been "D" shaped like a lot of knobs on radios etc it was a much easier system for the controls.

 

You get a shock when you look at diagrams for certain items now and see the prices they charge for spares, and I am glad it's only the control knob I am having trouble with.

 

Thanks once more

 

Terry

Link to comment
Share on other sites

....the control shaft on mine (though different model to yours) is "D" shaped, but the knob fitting over it has itself a long shaft which fits over it, and split longitudinally, leaving it a very loose fit on the shaft. Hence the inability (much of the time) to switch modes. (One of the family, who shall remain nameless, had, I think, tried to turn the knob in the wrong direction beyond the final stop :-S)

 

As I've said, I withdrew knob, bound round the split in its shaft tightly with electricians tape, restoring the function, and replaced it

 

(I also bought a replacement knob, but so far the original repair has worked, so i haven't had to use it).

 

I'm not saying you have the same problem, but you sure have similar symptoms.

Link to comment
Share on other sites

Hi Robinhood

 

I had a look at my Fridge this afternoon and mine is the same as yours with the control shaft D shaped,this is not split or misshapen but I still cannot get thr unit to work also I have noticed that the interiour light is now out. It has all the symptoms of a fuse but the only fuse I can find is on the split charge relay and that is ok.

 

Terry

Link to comment
Share on other sites

Hi Terry,

i`ve got the same model fridge and just been out to check the control switch.

 

It has 3 distinct setting 12V, 230V and Gas with a definite click between each setting.

 

A new control switch is needed.

 

Regards

Graham.

Link to comment
Share on other sites

Hi Graham

 

i have checked mine again and it has not got a click between the 3 steps, but it never has had this and I have had the vehicle from new.

 

Thanks the chaps above who have provided pdf's of the interior workings of the fridge I notice that the shaft of the control is sold as a single item so I assume this can be taken out of the control switch, I am going to strip the unit down again and see if I can see if this is the fault.

 

This still does not explain the fact the bulb has gone out, this was working when we came home from the Peterboro show, I have a feeling this may be a fuse but as I explained above the only fuse that I can find is on the split charge relay, this of course is only live when the engine is running and when the fridge was working the light would be on until you turned the Gas/12v and 240v control to the off Position if the control switch has got worse the this could explain why the bulb has gone out or may still be a fuse and until I get at this control and find out if it has a 12v live I will not know.

 

The Lunar Roadstar manual for my vehicle has on the front Revised April 2004 but it does mention inside 2006 models, but a lot of the things to do with the electrics or totally different on my vehicle to whats in the book, The main control box for the 240 volts is shown it the book as having 6 dc fuses mine has only 3 mains trip switches so I dont know where the 12v fuses are. The vehicle management panel in the book is shown as a KT9LM2 but mine on the vehicle is a CMS 2000 all computerized panel with no rocker switches as shown in the book.

 

Depending what I find when I strip the panel down I may put this thread on the main forum in the hopes that I may reach someone with a Lunar Roadstar and may know where the fuses are, I do not think any of the vehicle fuses would feed any of the rear of the vehicle.

 

Terry

 

 

 

 

 

Wooie - 2012-06-01 8:54 PM

 

Hi Terry,

i`ve got the same model fridge and just been out to check the control switch.

 

It has 3 distinct setting 12V, 230V and Gas with a definite click between each setting.

 

A new control switch is needed.

 

Regards

Graham.

Link to comment
Share on other sites

tp002c784tp002c784tp - 2012-06-01 8:19 PM

 

Hi Robinhood

 

I had a look at my Fridge this afternoon and mine is the same as yours with the control shaft D shaped,this is not split or misshapen but I still cannot get thr unit to work also I have noticed that the interiour light is now out. It has all the symptoms of a fuse but the only fuse I can find is on the split charge relay and that is ok.

 

Terry

 

There's always the possibility that your fridge's interior-light bulb has now failed.

 

Taking a simplistic view, it's reasonable to assume that 12V power to your fridge's electronics comes from a single source and, consequently, if you can obtain any reaction from the fridge when you turn it on (eg. an LED illuminating on the control-switch when you select gas operation) one might expect the interior-light to function. If you get no reaction when the fridge is turned on, then a blown fuse could be the cause. It should be easy enough to remove the interior-light bulb to check it.

Link to comment
Share on other sites

....as your interior light is not working, it is worthwhile searching for an additional fuse (other than the one on the split-charge feed) that would conventionally be in place to cover the control circuits and light.

 

The Dometic website (which used to be very good for manual downloads) does not give me the opportunity to download the manuals for your fridge, but there would normally be a (15-20A) fuse in the split-charge circuit (which is only live when the engine is running), and a (probably 2A) fuse in a permanently live circuit which would power the control panel, interior light, etc.

 

The challenge, of course, is to find out where your converter has put this particlur fuse.

Link to comment
Share on other sites

[

Hi Derek & Robinhood

 

 

I have looked in every cupboard and nook and cranny for a fuse box and I can not find one, I cannot believe with all the 12v goodies that is in the living quarters that there is not a fuse box some where.

 

I feel that as so much on the Fridge is 12v until I solve the fuse problem I cannot proceed with the problem with the control valve, I took the bulb out of the fridge and checked it and it is working so I think it's now down to finding the fuse box.

 

As a have stated before my Mains control box is a Hager with 3 mains trip switches, the one shown in my Lunar manuel is a PSU 2007 and this has 4 trip switches and 8 twelve volt fuses shown.

 

I am going to try the Lunar owners club to see if anyone can help with my problem and also email Lunar to see if they can help, I don't know how many MMM members look at the Hints and Tips section so I may also put this thread on the Main forum.

 

Thanks once more for all your help

 

Terry

 

 

 

 

 

 

tp002c784tp002c784tp - 2012-06-01 8:19 PM

 

Hi Robinhood

 

I had a look at my Fridge this afternoon and mine is the same as yours with the control shaft D shaped,this is not split or misshapen but I still cannot get thr unit to work also I have noticed that the interiour light is now out. It has all the symptoms of a fuse but the only fuse I can find is on the split charge relay and that is ok.

 

Terry

 

There's always the possibility that your fridge's interior-light bulb has now failed.

 

Taking a simplistic view, it's reasonable to assume that 12V power to your fridge's electronics comes from a single source and, consequently, if you can obtain any reaction from the fridge when you turn it on (eg. an LED illuminating on the control-switch when you select gas operation) one might expect the interior-light to function. If you get no reaction when the fridge is turned on, then a blown fuse could be the cause. It should be easy enough to remove the interior-light bulb to check it.

Link to comment
Share on other sites

tp002c784tp002c784tp - 2012-06-03 8:22 PM

 

Hi Graham

 

i have checked mine again and it has not got a click between the 3 steps, but it never has had this and I have had the vehicle from new.

 

 

 

 

Hi Terry,

 

you mention you`ve had the van from new, it might be worth ringing the dealer to ask where the fuses boxes are.

I know you`ve had the van for 5 years and the warranty has run out but it might still be worth a phone call or a quick visit if they are close enough.

 

Regards

Graham.

Link to comment
Share on other sites

Wooie - 2012-06-04 6:54 PM

 

tp002c784tp002c784tp - 2012-06-03 8:22 PM

 

Hi Graham

 

i have checked mine again and it has not got a click between the 3 steps, but it never has had this and I have had the vehicle from new.

 

 

 

 

Hi Terry,

 

you mention you`ve had the van from new, it might be worth ringing the dealer to ask where the fuses boxes are.

I know you`ve had the van for 5 years and the warranty has run out but it might still be worth a phone call or a quick visit if they are close enough.

 

Regards

Graham.

 

Hi Graham

 

That will be my next step on Wednesday I have emailed them but I don' expect an answer until later on this week

 

Thanks

 

Terry

Link to comment
Share on other sites

No idea if this might help...

 

http://www.motorhomefacts.com/forum-printtopic-1-112501-0-0-asc-viewresult-1.html

 

(incidentally, one would logically expect a rotary switch that can select a number of options to have a positive-stop at each option. Graham's switch operates in that manner and so does the switch on my Dometic 7-Series fridge-freezer. If your switch does not 'halt' at any of the gas, 12V or 230V positions, then something is wrong with it.)

Link to comment
Share on other sites

Derek Uzzell - 2012-06-05 8:41 AM

 

No idea if this might help...

 

http://www.motorhomefacts.com/forum-printtopic-1-112501-0-0-asc-viewresult-1.html

 

(incidentally, one would logically expect a rotary switch that can select a number of options to have a positive-stop at each option. Graham's switch operates in that manner and so does the switch on my Dometic 7-Series fridge-freezer. If your switch does not 'halt' at any of the gas, 12V or 230V positions, then something is wrong with it.)

 

Hi All

Well went out today determined to find the fuse box, sat on one of the seats looking at the stripped down Fridge and thought that one my vehicle a few years ago on my old trusty Talbot Highwayman having an electrical fault and been mistified where a cable had disappeared again after much head scratching I realised that it could have only gone under the van, crawling underneath I found a waterproof box with the cable inside covered in gangrene and broken, I thought surely not on a modern motorhome, I crawled under my van to the point where the harness went out of the van and thank god there was no fuse box, I followed the harness along the sill until it went up and this was in the pillar alongside the nearside door.

I went back in the van and realised that this was going into the Luton, crawled in the luton and found a brown box with no marks on at all two screws fixing it to the top of the wall, took out the screws and Walla a six fused box cried out with delight, I then thought about a motorhome sparky saying S**T forgot the fuse box where can I put that to be ackward.

 

But my cry's of delight faded when I found no fuses blown, i took the opportunity to find out what each fuse fed and recorded each one.

 

But it was now back to square one, then remembered the first posting by Keithl and wondered if I had the same fault so then tried to take out the unit with the fridge controls on, this is a long black box on top of the fridge that after you take the facia of you then take out two screws and the unit should slide forward but alas there is a would plinth between the top of the fridge and the underside of the worktops, this plinth cannot be removed as its screwed on the inside, back to the drawing board, The only way I can get out of this is try and file off an eight of an inch of the bottom of the plinth and hopefully slide the unit forward.

 

I am now thinking and hoping the like Keithl the shaft of the control has snapped inside and as no controls are moving the interior light or fridge is working.

If this is the fault the good thing is the shaft is only £4 cheap repair if I am right.

 

To Be continued !

 

Terry

Link to comment
Share on other sites

Hi All

 

a bit more success today with my ongoing fridge saga, With the aid of my dremel drill and a small circular saw blade I managed to cut a small section of the plinth and ease forward the panel with the broken control shaft.

 

The panel had a cover over the top of it and was parted by releasing three screws, once in side I found that the shaft had a round keep washer that rested in in a cup on the covers I removed the shaft and discovered on the end was a tee bar that fitted in the control and what looked like a broken eighth of an inch round dowel, this dowel had snapped off.

 

When I fitted the tee piece into the switch I could turn on the fridge, I turned on the control and on came the light and the gas.

 

I have ordered a new shaft even though I think I could fix the old one in with super glue, but I will see when the new shaft comes how long the dowel is on the end then I may try Keithl method of drilling a small hole in the broken dowel and remove with a thin self tapper.

 

Terry

Link to comment
Share on other sites

Hi Terry,

 

Glad you've finally found the problem.

 

It sounds almost exactly the same failure as the temp control on ours, but on ours it was a small 'D' shape dowel which engaged with the variable resistor on the board.

 

The new part for ours was yellow plastic not white and seemed to be a better material, time will tell!

 

Keith.

Link to comment
Share on other sites

Well done that man! All I'd say is, as you haven't jury-rigged a working bodge as Robin did (:-D) fit the new part straight off, and put it all back together. Superglue is not good on plastics generally, so if you try that and it fails after a few weeks/months, you'll only have to pull the lot apart again to fit the spare you've spent your cash buying. Once is enough, methinks. :-)
Link to comment
Share on other sites

Hi All

 

I am writing about they latest in my Fridge saga only because it could happen to other members and this may be a help to them.

 

I did mention that i have ordered a new shaft for my control switch, but i thought while I am waiting for it to arrive I will try and remove the broken piece in the main body of the switch. The switch that is fixed to the main circuit board is about the same size of a pound coin, I can not see the soldered part of the switch as I can not remove the panel far enough out, in the center of the switch I could see the broken shaft and is about an eight on diameter. Keithl mentioned that he drilled his broken shaft with a very fine drill and screwed in a very fine self tapper and managed to extract the broken end this way, Due to the tight space that I have I did not fancy doing this so I managed to move it with a sewing needle then managed to push it back in so I shoved a bit harder and managed to extract the broken section but also i pulled of the front plastic plate of the switch. Shock, Horror behind it was a four small brass springs less than a quarter of an inch long and about a sixteenth in diameter, one of these dropped down inside of the panel but I could see it, the other was last seen bouncing of the four walls and is gone for ever. After trying two or three shops I gave up but had a sudden brainwave that this spring is about the same diameter as the spring that holds the flint in a my old zippo lighter, Walla it is, cut it up into small sections and started the painful job of re assembling.

 

The new spring is steel so i hope it does not make a difference, the diameter is a bit smaller so I had to put a small blob of grease ( silicone ) to hold them in position and with a lot of puffing and panting and the aid of some angled long nose pliers slid the front plate back on, this plate has a series of very fine dowl's that locate it on to the main body of the switch with two at the top close together so you locate it in the right position. Bingo it worked.

 

Brian

 

This may be a bogged job but the switch main body is not shown as spare part and I would have had a job soldering a new one on as I cannot get the panel out far enough.

 

Terry

Link to comment
Share on other sites

  • 3 weeks later...

Hi All

 

Final chapter in the Fridge Saga, received the new shaft from Leisureshop direct very prompt service,reassembled the new shaft and great I now have three positive clicks between the three services this I have never had since I bought the vehicle.

 

As nothing was working until I obtained the new shaft I was not able to identify the fuse in my new found fuse box for the Fridge, so I pulled out each one in turn and could not believe that not one of the fuses fed the Fridge, so back to the drawing board.

 

Cutting a long story and hunt short I found an in line fuse in the bottom cupboard of the cooker the one where we store the pans stuck at the back, pulled the fuse and everything went out on the Fridge, so at last found it's 12v feed.

 

I have now found i think a lot about our Fridge that I did not know before and my obsession with finding the fuse box was in the end justified even though the fuses did not feed the unit, with all my testing I found that the Fridge will not work with out a twelve volt feed so my fault could have been a blown fuse.

 

Thank every one for there help and suggestions.

 

THE END

 

Terry

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...