Waeco / Dometic compressor fridges - Fault!!!!

Chris Shaw

Active Member
Joined
May 30, 2017
Hi all

I have a Dometic CRX80 compressor fridge which during various trips seemed to be running too much getting too hot (externally).

As we're about to go away for two weeks I decided to investigate only to discover the fan wasn't functioning and in fact was blown open circuit.

Background: I have an MPS35 power adapter, which takes in 240v AC and 12v DC and outputs 24v DC to the fridge which is supposed to be dual voltage 12/24v.

Once I got the fridge out and powered up I noticed the fan not running, left it for a bit because it was cold and assumed the fan was temperature controlled, still nothing. Check the connections on the controller and sure enough 26v on the input (with in tolerance ) also checked the fan connections on the controller, 26V!!!!! Now these small fans are used all over the computer industry and they are 12vDC !!! unscrewed the fan, sure enough 12vDC stamped on it... Removed the fan and applied 12vDC, dead as a dodo.

So either the controller has a fault or Dometic has a design flaw. Giving the benefit of the doubt lets assume the controller is supposed to educe the fan voltage from 24v nom to 12v nom.

Also there was a black wire tucked under the compressor which according to the wiring diagram on the side of the fridge doesn't exist!!

I bought the fridge in 2017, but it wasn't commissioned until May last year when I got my DVLA change over. So I guess I'm going to have an argument with Dometic customer services...

Any body else had a similar issue?
Anybody got a CRX fidge waiting to be installed who could look at the back and tell me if they have a loose black wire?


Chris
 

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Wanderer

Active Member
Joined
Mar 31, 2016
Location
Argyll & Bute - somtimes
Hi,
I have just checked my CRX50 and it is has 2 extra wires on the connector block.
A black wire goes to 'F' and a red wire which appears to go to + but this one is a bit hard to see.
Out of interest, why are you using the power block.
 

BigStevie

Active Member
Joined
May 17, 2017
Location
Highlands
Hi Chris,
I’ve an uninstalled CRX50 here and looking at it appears to be identical to yours, complete with a spare black cable. The wiring diagram sticker on the side of the fridge suggests the black ‘F’ cable is for the fan?
In addition to the main red power lead, there are two red cables connected to + on the block. One I imagine is for the fan, the other I can only guess goes to the control panel inside the fridge. I put the instruction book somewhere safe, so safe I can’t quite lay my paws on it...

Be interested to know how you get on. Good luck,

Stevie
 

Chris Shaw

Active Member
Joined
May 30, 2017
Hi,
I have just checked my CRX50 and it is has 2 extra wires on the connector block.
A black wire goes to 'F' and a red wire which appears to go to + but this one is a bit hard to see.
Out of interest, why are you using the power block.
Hi yeah I had removed the fan connections before taking the photo, you are right the + is red fan wire, and F is black. Not to be confused with the spare black wire I mentioned.

By power block I assume you mean the MPS35. That unit just provides an automatic switch between the leisure battery and the mains when I'm hooked up. It gives preference to the mains if it's available and take the load from the battery charger.

Chris
 

Chris Shaw

Active Member
Joined
May 30, 2017
Hi Chris,
I’ve an uninstalled CRX50 here and looking at it appears to be identical to yours, complete with a spare black cable. The wiring diagram sticker on the side of the fridge suggests the black ‘F’ cable is for the fan?
In addition to the main red power lead, there are two red cables connected to + on the block. One I imagine is for the fan, the other I can only guess goes to the control panel inside the fridge. I put the instruction book somewhere safe, so safe I can’t quite lay my paws on it...

Be interested to know how you get on. Good luck,

Stevie
Ok, thanks. So after a lot of investigation over the weekend, I found that the 26v on the fan outlet is a bit of a red herring, if the fan output is loaded it comes down to 12v, the reason I was reading 26v was because the fan was open circuit.

I was really surprised that there is no alarm for a failed fan!!!!!

Basically the fan is a bog standard 120mm PC cooling fan, 2 wire, 1700rpm, 70cfm, Ball race bearing, 0.3amp. So if that was replaced with a 3wire version which has a tacho output, the controller could monitor the tacho, as a PC does, and give an alarm warning.

No reply as yet from Dometic ! I guess at best they could offer me a replacement fan, as worst they could quote me for a new fan. Which according most Dometic spare websites charge £64!!!!!!!! I can get a much superior fan for £15 online.....


chris
 

BigStevie

Active Member
Joined
May 17, 2017
Location
Highlands
Why doesn’t the ridiculous spare part price surprise me... be interested to see how you get on with Dometic.

Maybe you could start marketing an upgrade kit on fleabay for £50? Make yourself a few quid Chris!

Stevie
 
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