Fridge problem - calling electrical wizards

[Bonsaiman]

Hi calling the electrical wizards

Three way fridge working fine on EHU and on gas but not on 12v when driving

Checked fuse on main fuse block and is okay (about my limit when it comes to electrics)

Is there another fuse nearer the fridge?

Any suggestions gratefully received

TIA

 

[Reallyretired]

A possibility is the 12v element is burnt-out. Test or open circuit with a multimeter. Not too difficult to replace, i did one many years ago.

 

[GeoffnDee]

Which make and model is the fridge ?

 

[namwaldog]

I think your MH may be on a Renault base so probably different from our 2010, Dcato based, Burstner, but perhaps worth mentioning......

Our 12v stopped working on the Dometic 8xxx series and a 20A fuse near to the +ve terminal of the cab battery was the culprit.

 

[GeoffnDee]

If your PSU is a Sargent EC200 / 2007 unit you may find the 20amp fridge fuse (along with others) in a separate module EM50

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[Bonsaiman]

A possibility is the 12v element is burnt-out. Test or open circuit with a multimeter. Not too difficult to replace, i did one many years ago.

Thanks, where would I find it

I think your MH may be on a Renault base so probably different from our 2010, Dcato based, Burstner, but perhaps worth mentioning......

Our 12v stopped working on the Dometic 8xxx series and a 20A fuse near to the +ve terminal of the cab battery was the culprit.

Thanks, just checked and no fuse other than main 40amp

If your PSU is a Sargent EC200 / 2007 unit you may find the 20amp fridge fuse (along with others) in a separate module EM50

Thanks, no it’s a Calira unit and the 20amp fuse is fine

 

[Bonsaiman]

Which make and model is the fridge ?

It’s a Dometic RM 8551 I believe and it’s the only manual the previous owner didn’t leave

 

[GeoffnDee]

It may not help at the moment ,but, there are manuals that can be down loaded for the Dometic RM8xxx series fridges on page two of Manuals for Motorhome stuff that can be found in the resources section (bottom of this page). There is a fuse shown on the fridge power module , but I do no know if this would cause your problem if faulty.

 

[Cush]

How effective should the 12v while driving cooling be. Mine had only ever held the temperature constant or slowed it from warming. May be broken too

 

[tonyidle]

It should be the same as on gas or mains. The usual problem is the converter scrimping on the wire size if the fridge is some distance from the starter battery.

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[Cush]

Thanks tonyidle .

 

[Reallyretired]

How effective should the 12v while driving cooling be. Mine had only ever held the temperature constant or slowed it from warming. May be broken too

12v on mine is as effective as other power sources in fact if there's enough sunshine I run it on 12v during the day fine even in 30+C

 

[Spanner]

Different fridge (Thetford) but when ours wasn’t working properly on 12v it was a poor electrical connection at the rear of the fridge. Fortunately with the lower vent removed I could see the wiring plug and sockets which had a burnt terminal. The thickest pair of cables will be the 12 volt feed, check across the pair with a multimeter, you should have 12-14 volts with the engine running and the fridge on. If you have 12 volts at the connection then you may have a failed 12v element easily checked for continuity with a multimeter.

 

[herald_400rl]

Our fuse for the fridge on 12v is located in the engine compartment near the battery in what looks like a box added for MH functions when on the move like split charge and fridge.

 

[mitzimad]

usually a fuse close to the vehicle battery

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[Bonsaiman]

It may not help at the moment ,but, there are manuals that can be down loaded for the Dometic RM8xxx series fridges on page two of Manuals for Motorhome stuff that can be found in the resources section (bottom of this page). There is a fuse shown on the fridge power module , but I do no know if this would cause your problem if faulty.

WOW thanks didn’t realise there was so much info available on MHF

Different fridge (Thetford) but when ours wasn’t working properly on 12v it was a poor electrical connection at the rear of the fridge. Fortunately with the lower vent removed I could see the wiring plug and sockets which had a burnt terminal. The thickest pair of cables will be the 12 volt feed, check across the pair with a multimeter, you should have 12-14 volts with the engine running and the fridge on. If you have 12 volts at the connection then you may have a failed 12v element easily checked for continuity with a multimeter.

Thanks, going to take bottom vent off and have a look, also to see if there is another fuse on or near fridge

Our fuse for the fridge on 12v is located in the engine compartment near the battery in what looks like a box added for MH functions when on the move like split charge and fridge.

usually a fuse close to the vehicle battery

Thanks, my battery is in the cab and have checked for additional fuse and there is none

 

[herald_400rl]

Thanks, my battery is in the cab and have checked for additional fuse and there is none

Just to confirm that's the "van" battery and not leisure battery?

 

[Bonsaiman]

Just to confirm that's the "van" battery and not leisure battery?

Yes, starter (van) battery is in a well between the seats and the hab battery is in a cupboard in the back