12V problems

[steviemick]

Hi I have just got a hymer 820S year 2001 after having a very straight forward Bessacar for the last 12 years. It has been plugged into mains since I bought it at a friends house in storage and I have just moved it to a caravan storage place and when pulling up could not get the step to come out. none of the internal lights are working either so it appears the 12v is not working only the fridge. The fridge was left on which possibly drained the leisure battery but I ran the engine to charge them up again to full and the 12v is still not working. Have checked fuses in the electrobox and everything seems to be ok, has anyone any ideas please? *-)

[Budgie823]

Hi, I had the exact same problem very recently and it turned out I had inadvertently knocked the system shutdown button isolating the 12v system.

[StuartO]

The leisure batteries could be duff - especially if they are the originals, now 15 years old.  That's certainly the first thing to check properly because of the risk of knock-on damage if you try to keep flogging a dead horse with them.

 

You don't need to replace the original Exide gel batteries with the same, so you could use much cheaper Bosch S5 or Varta Silver replacements if you prefer.  Your Electroblock is not the type to cope with AGMs so avoid those.

 

This millenium S Class series were magnificently designed, equipped and built but this vehicle is now 15 years old and will probably benefit from an expert assessment and refurb of the electrics - why don't you take it to AandA Caravans, where they have replacement stuff in stock as well as the expertise to diagnose and fix.

 

[aandncaravan]

Stuart0, thank you, that is quite an endorsement considering all the opposing discussions we have had on here?

It is really appreciated.

 

 

Steviemick, Stuart is right check the batteries first, most Schaudt Elektroblock problems (just like the majority of Motorhome power/charger units) start from a battery past it's best.

 

Check near to the habitation batteries for two fuses, normally a large style Red 50amp and a small 2a. Removing the 50amp usually causes the Frost Protection Valve to trigger and dump it's water so lock it 'up' with a peg or get someone to hold it up while you check this fuse. Once the fuse is replaced the FPV should latch without being held.

 

The 2a fuse is the EBL battery 'sense' circuit which the EBL uses to ascertain the battery voltage. If the 2a fuse is corroded it can lead to a voltage drop making the EBL believe that the battery voltage is lower than it is, so it won't switch on. Suggest you replace this fuse as a matter of course? A 3a fuse is ok if you don't have a 2a but suggest you don't go any higher?

 

 

I assume the Elektroblock is an EBL 99? If so check that the switch on the front of the EBL is 'On/Ein', i.e. pushed in at the top and the opposite to the Uk norm of being pushed in at the bottom.

Using this switch to turn off the EBL sometimes results in the unit not powering back up when the electronics get a bit tired so suggest you don't use it?

 

 

Under the bonnet you will find 3 'after market' fuses right next to the Starter battery, not vehicle fuses in the vehicle fuse box. These are 'loose', look like an 'add-on' and always next to the Starter battery, often above it. You are looking for 3 fuses clustered together, usually a big Red 50A, small Grey 2A and Yellow 20A.

 

Check these fuses one at a time, so you don't mix them up. If your habitation batteries or Starter battery are past their best the 20a fuse tends to show signs of melting/running hot. If your batteries are rubbish the Red 50a will often be blown.

 

Again you are checking all the fuses for signs of poor connectivity, not just that they are 'intact'.

The fuse legs should be shiny, not dull and pitted.

 

We suggest you replace them as a matter of course if they look like they might be over 10 years old.

 

If you are used to British vehicles, you are probably familiar with the control panel above the door turning off every journey? Some people manually turn off the control panel every journey to emulate the British way of operating. This is not a good idea with Continental built vans like Hymer, Burstner, etc. as it just results in unnecessary wear on the switches. There is no reason to turn it off while on a journey or leaving the vehicle for a day out.

Best to leave the control panel on, until you put it into short/long term storage.

 

 

Use the Control panel to read off the battery voltages (this function is usually still available even when the EBL 99 is 'down') please report back what you see for both Starter and Habitation?

Then Start the engine and re-record the voltages. Turn off the engine, Plug in to 230v, if available, wait 30 seconds and again record the voltages.

 

Email us via the web site if you need more help, just Google A and N Caravan services, but I will try and get back on here later.