Fridge has just stopped working on 12v

We have a 3 way Dometic fridge in our 2009 VW T5 Trident.

It works fine on mains or gas but has suddenly stopped working when driving the van. It's never played up before.

The red switch on the left end of the fridge control panel doesn't light up now.

Is it a 12volt in-line fuse that's gone?

If so, where might I find it?

Thanks.

On our T5-based Trooper, the fuses are in front of the engine battery (in our case under the plastic battery cover, though they are not always fitted). The Trident is probably the same (but may not be!).

Ours has a fuse near the engine battery and also a relay under the driver's seat, which allows the 12V through when the ignition is on. It may be the relay but is more likely to be the fuse.

Incidentally, I assume you have actually checked that the fridge isn't cooling? The red light in our switch stopped working yonks ago but the fridge still works.  I have obtained a replacement switch but it's still on my list of jobs to do.

cheers
Roger

-mojo- wrote:On our T5-based Trooper, the fuses are in front of the engine battery (in our case under the plastic battery cover, though they are not always fitted). The Trident is probably the same (but may not be!).

Same as mine (Duetto Ford Transit) and suspect Markus is likely to find his round there....somewhere! My fuse holder is actually above the battery underneath the scuttle so not visible straight away. Could be worth poking around that area. I had problems with my fuse which kept blowing so eventually had a brand new holder wired in and stuck brand new fuses in at the same time. Since then i've had no problems.

Thanks for info.
I've looked under the bonnet, under the battery cover, in front of the vehicle battery are 3 fuses in a housing. I've checked them and they are fine, so I'm guessing I should look elsewhere.
I have looked at the leisure battery under the drivers seat, there's a fuse but it's for all of the 12v system and it's fine as are the 12v lights etc.
It's only the fridge that has a problem.

So I'm wondering; if it's one of those fuses by the vehicle battery that look fine, then maybe the relay is faulty as Roger said.

Thought this might turn out to be something easy but seems not

I'll keep looking

Have you tried blipping the throttle then looking at the switch? The relay sometimes takes a bit of waking up. Also try flicking the switch on and off a few times with the engine running, this works every time for us. Dry contacts in the switch I think. On my to do list...
Al.

Mine has two relays, I believe one is for the fridge and the other turns off the 12v to the habitation area when driving. If yours also has two relays, maybe try swapping them to see if that identifies whether one is faulty?


Cheers
Roger

no luck so far, tried all the suggestions on offer.
I put a volt meter on the red switch connections with the engine running,
no reading, so I'll assume no supply getting to fridge.
Only found one relay.
 I'm assuming the 12volt supply for the fridge comes from the vehicle battery when driving, is that correct?
I think I'll get a new relay and see if that makes a difference.

It's the alternator that triggers the relay, both batteries then get charged and the fridge is then powered by the 12 volt supply.

The engine alternator supplies power to the habitation battery as well as the fridge.
You have checked and found no voltage at the fridge. Run the engine and check for a raised voltage at the hab battery.  If there is raised voltage, the relay is working and the fault is probably at the fridge. If there is no raised voltage at the battery, then it's probably the relay.
This theory is predicated on there being only one (split charge) relay.  Keith

KMRTOPAZ wrote:The engine alternator supplies power to the habitation battery as well as the fridge.
You have checked and found no voltage at the fridge. Run the engine and check for a raised voltage at the hab battery.  If there is raised voltage, the relay is working and the fault is probably at the fridge. If there is no raised voltage at the battery, then it's probably the relay.
This theory is predicated on there being only one (split charge) relay.  Keith

Right then, thanks for that Keith.

Just put the voltmeter on the leisure battery and it was 12.7
and with the engine running, (and revving) guess what, it was still 12.7

So I'll go shopping for a relay to replace the only one I can find under the bonnet ( next to the battery)
It's a 30 amp 4 pin and I'm presuming that's the one cus there certainly isn't one near the leisure battery

I've got my fingers crossed now...

No joy yet.
Still no red light on the 12v switch.

I've replaced the relay and there is still no increase in voltmeter reading on the leisure battery when engine running.

Any fuses I can find are all ok.

In my vehicle battery compartment there is a small fuse box with a perspex cover containing just 3 nice clean unblown fuses. Next to it is one relay, (now replaced)
There are no other fuses or relays under the bonnet

Wondering where to look now.

I would've thought you should have two relays. This diagram helped me when I had similar problems. One of my relays had burnt out it's holder, I had to replace the whole setup.

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Those are always the most difficult to diagnose Markus.

Glad you got it fixed in the end. At least the beer will be nice and cold at the end of your journeys from now on.
Can't be bad!!