WAECO FRIDGE PROBLEM.

[Shiny Paul.]

Good morning,
I am new to this forum but very glad I have found you guys.
I have a 2012 Mercedes Sprinter race van and I have a problem with the Fridge.
Firstly the fridge works fine when the van is running, but when the engine is off and the fridge is relying on the 2x 110a leisure batteries the fridge works ok for a little while, perhaps an hour, then starts to warm up and the red warning light starts blinking approx once every 5 seconds. The manual shows this as a voltage fault but the volt meter is showing 12.7volt, which is well above the low voltage cut off.
Any help would be much appreciated.
Paul.

 

[Sundowners]

It does sound as though the fridge is running off the engine battery while driving, but not switching to the leisure batteries when you stop the engine, I know nothing about these fridges or how they would be wired but I would check out all the fuses, in particular at the back/supply to the fridge.
I THINK there would be three basic power supplies (12v) one constant, one from the engine battery and the one I imagine you have a problem with.
Somebody who knows more than me will undoubtedly be along to add their knowledge!!!

 

[tonyidle]

A better check would be to measure the voltage at the fridge terminals - there's no reason to assume it will be the same as that leaving the battery.

 

[jezport]

Have you checked the voltage at the fridge, not the battery end.

 

[Shiny Paul.]

The voltage is the same at the fridge as at the battery, I have checked that.

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[jezport]

Did you check with the fridge running and cooling

 

[mitzimad]

if the fridge works whilst running its definitly not a fridge problem these compressor fridges are wired to the leisure batteries usually
its running when travelling so the obvious culprits are your batteries or wiring to the fridge depending how difficult it is i would run some suitably sized cable temporary direct from bats to fridge see what happens
i seem to remember reading somewhere about connections in the fridge corroding so if possible try direct to compressor

 

[Shiny Paul.]

Did you check with the fridge running and cooling

No only checked it to make sure it was getting full battery voltage, should there be a voltage difference when it is running ??

 

[34127]

Yes, there will be a voltage drop in the cable which may be the cause of your problem.
Also, when the compressor starts up it will take a much higher initial current and the voltage will drop even lower.

 

[Shiny Paul.]

Ok thank you, i will pull the fridge out again tonight and test it on start up and in operation.

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[Shiny Paul.]

Ok problem found....when I checked the voltage again last night it was showing 12.7v at the fridge until the compressor started up and then it dropped to 10.2v, which is below the cut out.
I hard wired the fridge directly to the battery and it works perfectly, so it is the wiring between the fusebox and the fridge, not really surprising if you saw the bodged up connections on this wiring, and the fact that at the fusebox end the loom is Brown = positve and the blue is earth BUT whenby the time it reaches the fridge the polarity is reversed.
So this weekends job is to rewire it properly
Thanks everybody for the help, really glad I joined this forum now .

 

[WynandJean]

Hello and welcome from West Midlands.



Wyn

 

[jezport]

Ok problem found....when I checked the voltage again last night it was showing 12.7v at the fridge until the compressor started up and then it dropped to 10.2v, which is below the cut out.
I hard wired the fridge directly to the battery and it works perfectly, so it is the wiring between the fusebox and the fridge, not really surprising if you saw the bodged up connections on this wiring, and the fact that at the fusebox end the loom is Brown = positve and the blue is earth BUT whenby the time it reaches the fridge the polarity is reversed.
So this weekends job is to rewire it properly
Thanks everybody for the help, really glad I joined this forum now .

There you go, thats why I suggested the voltage was checked when turned on
Glad that you are sorted.

 

[Shiny Paul.]

Perfect, thanks very much for the suggestion.

 

[EuroTrotters]

I have just been to look at one on a narrow boat.

Same issue.

The voltage at the plug was 12.4

But, upon removing the plug, it was wired with .5 mm cable 5m from the batteries.

I advised him to get the cable replaced with 4mm.

Fridge now works fine.

TM

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[34127]

When you are rewiring the fridge, Waeco suggest that it is wired directly to the battery via a fuse and not to put additional isolating switches in the circuit.

 

[Shiny Paul.]

Ok that makes sense, but I do not want the fridge running permanently but I guess it is just as easy to pull the fuse.

 

[34127]

Yes, Waeco advise you to turn the control knob to 0 to switch it off and then remove the cable from the battery (or remove the fuse).

 

[Shiny Paul.]

Great that is easy to do, Thank you very much.

 

[autorouter]

at the fusebox end the loom is Brown = positve and the blue is earth BUT whenby the time it reaches the fridge the polarity is reversed.

Hymer MHs are wired blue = positive, brown = negative. I presume it's a German colour code.
When I bought a replacement water pump in Italy I had to wire it blue to brown, brown to blue.

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[mitzimad]

i suspect waeco say no switches because most people would use something cheap and not up to the job might be best if you need a switch to use it with a relay and 6 mm cable

 

[EuroTrotters]

Hymer MHs are wired blue = positive, brown = negative. I presume it's a German colour code.
When I bought a replacement water pump in Italy I had to wire it blue to brown, brown to blue.

How a blew an Inverter up some time back (With no reverse polarity protection).

 

[rod_vw]

I know this is an old thread but I thought it worthwhile to remind everyone working on German standard vehicle wiring that BROWN is NEGATIVE (ground or chassis) potential and will often be marked with the number 31 on terminals.

This can make for a confusing connection point where UK standard mains electrical points are grounded to chassis with a Green/Yellow wire and German (DIN) 12v electrics are grounded to the same point with a Brown wire!

Moral of story - Be Careful.

Rod

 

[treetops1]

Most people like ourself run the fringe on gas when stopped . You don't need to worry about your batteries and you will find you use very little gas ,it only like a pilot light so lasts a long time ,Save you elec for the TV lol.

 

[jezport]

Most people like ourself run the fringe on gas when stopped . You don't need to worry about your batteries and you will find you use very little gas ,it only like a pilot light so lasts a long time ,Save you elec for the TV lol.

This is a waeco fridge. So doesn't use gas it's 12v

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[treetops1]

Sorry I was unaware that the waeco did not have gas .Sounds as though it's not versatile enough for a motorhome .I feel in bad weather ,poor light .no access to electricity .gas is essential .

 

[jezport]

Sorry I was unaware that the waeco did not have gas .Sounds as though it's not versatile enough for a motorhome .I feel in bad weather ,poor light .no access to electricity .gas is essential .

The compressor fridges use very little electric and are generally smaller models

 

[treetops1]

You live and learn lol