Topaz Intermittent fault with 12v fridge

Hi Guy's
I have a VW AutoSleeper Topaz with an Electrolux RM 427. When I start the engine the fridge light is on which indicates that the fridge is working on 12v. The light can stay on for between 5 & 15 minutes then goes off. If I stop and immediately restart the engine the light remains off, if the engine is off for ,say, 5 minutes, the light will go off again for the same 5 to 15 minutes.

Any ideas?

Keith

First thing I'd check is the fuse that is usually located in the engine compartment. They have a reputation for overheating and becoming intermittent. Quite often they are found to be a molten mess!

Thanks for a quick reply, I'll go have a look as soon as the weather clears up.

Keith,

On "Petal" when we first took possession we had to flick the 12v switch "On" and "Off" for up to a dozen times before the red light would come on and stay on when we were on the road!

After four or five times the switch started to work normally so I presumed that in her previous life the 12v function on "Petal's" fridge was not used very often and it needed a good few "On"/"Off" switches to clean up the points.

Hope this helps.

Best regards,

Ian

Hi Ian

Thanks for that, I'll also try that tomorrow.

Hi Guy's

Sorry for the delay getting back.....you know what its like!

Tried flicking the switch on & off a dozen or so times.....no change.

Checked all the fuses that I could find, cleaned and sprayed them...no change.

Had the engine running, fridge light on, 2 minutes running the light goes off, stop the engine and immediately re-start the light comes on but goes out within 2 seconds.

I'd guess at a faulty relay, but I have no idea where it would be on your van.

Frank

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I'm not sure about the newest vw's but the relays always used to be mounted under the bonnet - see the picture in the thread above.

Peter

PS The fuse for the fridge feed is also there so if you haven't seen the relays you haven't cleaned the right fuse.

Yeah, I cleaned all 3 fuses that are by the relay's under the bonnet. Any ideas on how to test for the correct relay, then how to test that relay.

The quickest way is my substitution, swap two relays of the same type and see if the fault swaps with them.

Peter

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This diagram should help with checking relay operation.

Peter

Thanks for the info Peter.
I have isolated the relay that works the fridge and replaced it with a new one as it was only £2.40 from my local Maplin. Unfortunately it didn't improve things.

When my van was only 12 months old it had a very similar problem. There is an in line connector behind the fridge, the 12v pin for the fridge heater element was not good and was getting hot, increasing the resistance and then stopping the fridge working. The connector case was translucent and the browning caused by heat from the pin was visible.

You do not necessarily have any similar connectors in circuit but it does seem that some terminal or connection is loose, just enough to generate heat and stop the fridge working till it all cools down again - could take some finding!

Peter

Thanks for another suggestion Peter, I'll have a look when we return from holiday.

OK guy's I'm back from holiday. I removed the fridge and re-made all joints in the 12v wiring around the switch, the wire that goes from the switch to the fridge has no more joints. I have put the fridge back in place but the problem still remains. Tomorrow I will check to see if, when, the switch light goes out, is there still power going too the switch, should have done this while the fridge was out so will check that the power is heading that way from the relay after the light goes out.

OK, I've checked the power supply and the fuse for the fridge near the relay's has power to both sides ( removed the fuse and put a meter on each side ) either with the engine running or stopped

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You will see from the circuit diagram that you will always have 12v either side of the fuse. The places to check are at pin 87 of the relay and at the fridge itself. There should be no 12v until the ignition is switched on and the relay operates. Don't forget to check that the negative connections are good as well because a high resistance on that half of the circuit could also cause the fault.

Peter