Fridge isnt working on Battery - there's no power!

Post by **ringo** » 23 Jul 2007, 21:04

I've just serviced the fridge and fitted two pc fans to get the air circulating a bit better - and now im glad to say that after two hours on gas, the fridge now works on gas.

While it was out, but connected, i started the engine and checked the 12v power leads for the expected 13.8v.

Nothing.

So, whats the craic with the 12v on the fridge - is it related anyway to the zig unit - or is it just connected to some electrical wizardry (ermmm, relay) in the engine bay that provides power when the alternator is charging ?

I have a feeling the fuse has gone. Or the relay. Where the hell are they usually located ? I imagine thats conversion specific...

Any ideas ?

Thanks

Ringo

Post by **Mark S** » 23 Jul 2007, 22:07

On the Westfalia the fridge is nothing to do with the Zig unit: all that does is supply two 12v feeds, one for each battery. The fridge will be supplied from the leisure battery, so the first thing to do is check the fuse. You say that you have power at the fridge, so I suspect that it is your relay that is at fault. On mine this is located close to the fridge. Its purpose is to allow power to the fridge only when the engine is running, so I would imagine that it has also got some sort of feed from the alternator to provide the switching. I would imagine that this relay is the source of the problem. Also, it sounds basic, but check your fridge has an earth back to the chassis.

Post by **Nicola&Tony** » 23 Jul 2007, 22:40

Mark S wrote:The fridge will be supplied from the leisure battery . . .

You say that you have power at the fridge, so I suspect that it is your relay that is at fault. . . Its purpose is to allow power to the fridge only when the engine is running,

I thought that if a fridge has electronic ignition rather than the push button (Piezo) ignition then this will be supplied from the leisure battery, but otherwise fridge battery power comes from the engine battery and is only to be used whilst the engine is running (as you mentioned in your reply Mark)?

Tony

Post by **Bowton Lad** » 23 Jul 2007, 23:18

Nicola&Tony wrote:
Mark S wrote:The fridge will be supplied from the leisure battery . . .

You say that you have power at the fridge, so I suspect that it is your relay that is at fault. . . Its purpose is to allow power to the fridge only when the engine is running,

I thought that if a fridge has electronic ignition rather than the push button (Piezo) ignition then this will be supplied from the leisure battery, but otherwise fridge battery power comes from the engine battery and is only to be used whilst the engine is running (as you mentioned in your reply Mark)?

Tony

You're right, Tony, the 12v power for the fridge is supplied by the alternator when the engine is running. When stationary, it's gas or 230v electrickery for those posh peeps with a 3 way fridge.

Post by **Mark S** » 24 Jul 2007, 06:04

You're all correct about the alternator but it needs some clarification: the fridge is normally only powered when the engine is running, yes. But the power feed to the fridge, just like every other piece of electrical equipment in the vehicle, is still connected back to a battery, not directly to the alternator itself. The fridge is a little different in that it has got a relay in line to avoid draining said battery and this relay must be connected to the charging light ciruitry of the alternator somehow so that the relay knows when the engine is running and hence when to allow the juice through to the fridge. On my bus (Westy) the main power feed to the fridge is from the leisure battery via a fuseway behind the driver's seat, but others may well be different and it doesn't actually matter which battery, because it is not powered when static.

There is a similar relay device for battery charging when the engine is running. Alternators only have one main terminal. At rest the 2 batteries are separate circuits but when running their positives are connected for charging (so the fridge is actually fed by both batteries!). This relay could well be combined with the fridge relay. If you look behind your fridge you will see some fairly hefty cables which I imagine are something to do with this circuit.

Approach in any case will probably be to follow the wiring back from the fridge until a point where voltage is detected and then work out what is knackered. Assuming the wiring is OK, as there is no power at the fridge it is probably best to start with the fuses (incl leisure fuses).

Post by **hembo666** » 24 Jul 2007, 06:26

Ringo, maybe me and you can have a head scratch together at costock over this one as we have the same problem, my split charge system doesnt work either and im not sure if its related.

Post by **ringo** » 24 Jul 2007, 11:23

Indeed hembo. I've sorted my split charge system out (dodgy relay) but i have no idea where my relay or fuse is for the fridge. I will have a look in the engine bay at some suspect fuses - but i have no idea where the relay would be.

If you kind find your relay hembo - we will be half way there. I will bring my multimeter and we will get it sorted...

Thanks for the replies.

Ringo

Post by **hembo666** » 01 Aug 2007, 21:01

sorted my fridge and split charge system i think. only time will tell but i found 2 blown line fuses hidden in a dark corner of the battery compartment under the relay

Post by **ringo** » 02 Aug 2007, 06:45

Good stuff.

I sorted mine too. Found yet another relay under the drivers seat that was not working. Replaced that and now i get 12v at the fridge when the engines running. Not tested it yet though....

Post by **Mark S** » 02 Aug 2007, 18:36

I think I can help with the relay under the seat - in mine it's to charge the leisure battery when the engine is running. Should take the blue wire from the alternator to trigger the connection and basically joins the 2 batteries together. In some systems I believe it doubles as the fridge relay too. If it's shot, you'll maybe not charge the leisure battery but could also break the feed to trigger the fridge relay.

Post by **ringo** » 02 Aug 2007, 22:20

Thanks dude - there are two of them - a few months ago i realised that the split charge relay was knackered - so changed that and made my retro fitted split charge redundant...
While i was fixing that i thought - i wonder what that relay does...
So now i know!

Ringo

Post by **R0B** » 02 Aug 2007, 23:45

believe me mate you will need to do a million miles in one go to get the 12v system to do much.and 2 million to get any ice on the freezer box...

Not tested it yet though....

Post by **ringo** » 03 Aug 2007, 08:47

sukhoi27 wrote:believe me mate you will need to do a million miles in one go to get the 12v system to do much.and 2 million to get any ice on the freezer box...

Not tested it yet though....

Well, i will see tonight - driving to the Champagne region of France - i want my wine cold!

Ringo

Post by **hembo666** » 03 Aug 2007, 18:22

believe me mate you will need to do a million miles in one go to get the 12v system to do much.and 2 million to get any ice on the freezer box

chilled cans of beer from warm to the touch to ice cold in a 30 min drive.

Thats me happy

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Fridge isnt working on Battery - there's no power!

Fridge isnt working on Battery - there's no power!

Fridge isn't working on Battery - there's no power