Club 80-90 Forums

Hello All,
I had a strange occurance the other day. I have a 1990 2.1 ltr waterbox Auto Sleeper Trident with the original, installed electrolux fridge. I recently had the fridge on all the time (via the starter/engine battery) for a 4 hour journey. Near the end of the journey, my camper just lost power, and I rolled to a stop. When I stopped, the engine was dead and there was no electrical power since my new electric power steering wasn't working. I tried turning the ignition on, but the engine would not crank at all. This was strange since the battery is less than a year old and I've had no starting problems in any way even over our very cold days this winter. After phoning the AA, that is after 15 minutes or so, I tried the ignition again and the engine turned over. Because I was close to where I was going, I turned off the fridge, and I proceeded to my destination where I had arranged to meet the AA man.

The AA man couldn't find anything wrong with the engine, my battery, nor the alternator, and everything seemed OK. I told him, however, that I had the fridge on for 4 hours so I wondered if that had anything to do with the problem. He then checked the battery again with the engine running and it was holding its charge, but when we turned on the fridge, his meter showed that the battery's voltage started to drop by a very small amount, and this seemed to be quite consistent. He then surmised that perhaps, over a four hour journey, the fridge was drawing ever so slightly more voltage from the battery than the alternator was recharging, so eventually, the battery got to 12 volts or less, and that effected the electrics and caused the loss of power etc.

So, has anyone else experienced this, and if so, why should it occur, and what was your solution?

Any help would be really welcome! Thanks!!

A few questions for you

I assume that you don't have the optional leisure battery fitted, correct ?

What's the voltage across the battery terminals when the van is running, fridge off. Do this at idle and around 2500 rpm ?

Do you know what the rating of the fridge is ?

First step is to decide if the charging system is below par, or if the draw from the fridge is too high.

I have a Trident and can probably post comparative figures later this morning

salgarfi wrote:When I stopped, the engine was dead and there was no electrical power since my new electric power steering wasn't working.

How new? Did the AA man check the voltage while you operated the steering? I'm not really familiar with electric power steering, but I know that they can draw a lot of current.

salgarfi wrote: fridge was drawing ever so slightly more voltage from the battery than the alternator was recharging, so eventually, the battery got to 12 volts or less, and that affected the electrics and caused the loss of power etc.

So, has anyone else experienced this, and if so, why should it occur, and what was your solution?

Any help would be really welcome! Thanks!!

The fridge should only draw 8-10A about the same as the headlamps it doesn't normally cause a problem. The electric power steering saps a lot more power especially more twisty the road,
As the AA man says you may be getting marginal on how much power you are using that the alternator can supply.
You need to check how many Amps you are using when everything is switched on compared to what the alternator can supply.
If the alternator voltage regulator has not been replaced with a higher voltage version 14.2V or 14.5V, replace it that will make the alternator work harder and keep the voltage above the minimum battery charging voltage threshold.

the fridge only takes 11amps at most , there is no way that should drop your battery whilst the alternator is running . you have either a wiring issue or a alternator problem i would say
first job is to ascertain the actual amperage the fridge is trying to take, but ill tell you now its not going to be more than a healthy alternator can produce, and thats a fact, the wiring to the fridge couldnt sub-stain that much draw . ( Autosleepers are known for under rated wiring to the fitted fridge in the first place )

The closest problem to yours was with Autohomes that I bought and the starter battery went flat whilst driving one night and had to be relayed home. I tested the wiring and found that someone previously had wired the leisure battery relay incorrectly - if it failed the leisure battery was charged but not the starter battery, of course, it should be wired the other way around. The reason for the relay failure was one of the relay coil connections had come off.

Just fired mine up and took some readings for comparison:

Fridge off;
Starter battery 14.3v
Leisure battery 14.25v

Fridge on
Starter battery 14.3v
Leisure battery 13.3v

Readings were virtually identical on fast idle (2200 rpm, engine was cold) or normal idle. Looks like my charging system is in good fettle

Do take a look at the current draw from your electric power assist system, as others have said the current draw from that could be very significant, but then again I assume you aren't circulating roundabouts all day so that isn't constant draw.

You might want to repeat the voltage test and watch what happens when you turn the steering wheel

I hope that helps

937carrera wrote:Just fired mine up and took some readings for comparison:

Fridge off;
Starter battery 14.3v
Leisure battery 14.25v

Fridge on
Starter battery 14.3v
Leisure battery 13.3v

Readings were virtually identical on fast idle (2200 rpm, engine was cold) or normal idle. Looks like my charging system is in good fettle

Do take a look at the current draw from your electric power assist system, as others have said the current draw from that could be very significant, but then again I assume you aren't circulating roundabouts all day so that isn't constant draw.




You might want to repeat the voltage test and watch what happens when you turn the steering wheel

I hope that helps

three way fridge?
wired to wrong battery is it is....
should be fed from main battery, so the fridge is as if it is a another leisure battery being fed from the main battery although in reality all a split charge does is join the two batteries together , for two reasons
1 so it is getting a share of the first hand charge direct from alternator
2 you can have a switch on the split charge to control when the leisure gets charged,

I'm not the one with the problem, but I'm happy mine (yes, 3 way) is wired correctly according to the original Autosleeper wiring diagram which James has enhanced at https://vwt25.blog/2016/05/13/zig-mc-2000-wiring/

I can see the logic for the Autosleeper wiring where the fridge is taking it's current from the leisure battery, rather than the start battery, though both are of course linked by the split charge relay. Interesting also to see the 0.05 volt drop with the extra cable length. At the end of the day I think it's 6 and two threes.

I did ask the OP if he had the leisure battery option on his van, as it was an optional extra.

Hello All, and thanks for your responses!

The fridge is wired to the starter battery, not the leisure battery. The battery is about a year old. After the car lost power, and then I drove it for ca 10 minutes to get to my destination and the van sat for around an hour until the AA man came, the battery charge was 13.9 volts. This was slightly lower than it should be (presumably because it discharged), but when we turned on the fridge while the van was idling, the voltage started to drop every few seconds by around a hundredth of a volt. It would waver a bit, but it seemed to be consistently dropping at a very slow rate. Now, a couple of months ago, I had all of the domestic appliances serviced and every thing was in order and the electrics (and gas) got a clean bill of health.

I'm still away from home, but when I get back I'll have the alternator and fridge electrics looked at.

Re the electric power steering, I was driving mainly on dual carriage ways so the roads weren't winding.

I drive back to Wales tomorrow, or Sunday, so I hope that 'Honoria' will behave herself - the fridge will be turned off!

The voltage drop every few seconds is indicative of either a cell down on the battery (check this with the battery disconnected), a load draining the battery, or more likely simply the battery resturning to it's rest state after being charged by the alternator at around 14V.

A fully charged battery, after resting, will show 12.6-12.7 volts, so the 13.9 volts must have beeen while the engine was running or shortly thereafter. My starter battery is 12.67v and the leisure 12.73 this morning, not having run since the meter readings were taken yesterday

Do you have access to a multimeter, they are incredibly useful and cheap as chips these days, well less than a tenner off ebay or if you are near a Screwfix £7.29 in your hands https://www.screwfix.com/p/lap-mas830b- ... _container

Good luck for the journey home, lights & heated window off as well unless you need them

937carrera wrote:The voltage drop every few seconds is indicative of either a cell down on the battery (check this with the battery disconnected), a load draining the battery, or more likely simply the battery resturning to it's rest state after being charged by the alternator at around 14V.

The engine was running.

@Salgarfi - do you know which alternator you have?

In my experience, any significant load will show as a voltage drop on the battery, even when you have a biggish alternator, good wiring, and a healthy, charged battery. I have a voltmeter on my dash, and I can see a voltage drop whenever I turn on the fridge, or the headlights, or the blower motor etc. I swapped my alternator to a 90A version, and the drop is less, but it's still there. When the battery is fully charged, and there's only minimal load, my battery voltage sits at 14.5V when the engine is running. A drop of 0.1 or 0.2V for any of the above items is what I usually see. But with that sort of drop, the voltage at the battery is still comfortably above what it needs to be to put charge in the battery, so it's not a problem.

So I can't see the fridge being the problem in your case. As suggested above, get yourself a cheap multimeter, then watch what happens to the voltage when you turn the steering from lock to lock. I reckon power steering may draw 5 to 10x the current of your fridge. If you have one of the smaller alternators it may not be up to the job of running power steering AND a fridge.

bigherb wrote: The engine was running.

I thought so at first but it doesn't quite say that

salgarfi wrote: the van sat for around an hour until the AA man came, the battery charge was 13.9 volts.

If the engine was running do you think 13.9 volts is a bit low for idle with no other loads on - it might be an indicator of a weak alternator / voltage regulator

937carrera wrote: I thought so at first but it doesn't quite say that

salgarfi wrote: the van sat for around an hour until the AA man came, the battery charge was 13.9 volts.

salgarfi wrote: but when we turned on the fridge while the van was idling, the voltage started to drop every few seconds by around a hundredth of a volt.

937carrera wrote: If the engine was running do you think 13.9 volts is a bit low for idle with no other loads on - it might be an indicator of a weak alternator / voltage regulator

13.8V is the minimum to fully charge the battery but until we get some more accurate readings we are only guessing the problem.