Waeco crx0500 fridge not working [Resolved]

[Handypete]

My van has a waeco crx0500 12v fridge fitted. It used to run both when on hook up or off the leisure battery when off grid, now however it only works when on mains and when not connected to mains shows a fault of “excessive fan current” which is explained in the manual as the fan load on the electronics unit is more than 1 amp.
I thought it might be the battery but I’ve tried another new one and that hasn’t cured it.
I've tried to get an engineer from the local dometic (waeco) agent to look at it but they seem to be too busy to return calls.
Can anyone suggest a likely cause and or recommend an engineer who will look at it in the Bedfordshire area
thanks

 

[Johnod17]

Could be a faulty fan ,does it rotate?
some fans have a feed back to say it is rotating,these will have 3 wires on the fan.

 

[Handypete]

Could be a faulty fan ,does it rotate?
some fans have a feed back to say it is rotating,these will have 3 wires on the fan.

Fan rotates fine when on electric hook up not at all the rest of the time

 

[DXX]

My van has a waeco crx0500 12v fridge fitted. It used to run both when on hook up or off the leisure battery when off grid, now however it only works when on mains and when not connected to mains shows a fault of “excessive fan current” which is explained in the manual as the fan load on the electronics unit is more than 1 amp.
I thought it might be the battery but I’ve tried another new one and that hasn’t cured it.
I've tried to get an engineer from the local dometic (waeco) agent to look at it but they seem to be too busy to return calls.
Can anyone suggest a likely cause and or recommend an engineer who will look at it in the Bedfordshire area
thanks

Could the excessive current be caused by low voltage, less than 12V?

 

[AussieMick]

Can you put a multimeter on terminals at back of fridge when on battery power and check the supply voltage there.
It should be nearly the same as battery.
I assume your battery is fully charged as many fridge problems on this forum turn out to be battery related.

 

[Handypete]

Thanks for the replies.
On further investigation
With mains connected 13.6 v at fridge
12.3v at battery with mains connected
With mains disconnected 12.3v at battery and 11.5v at fridge ( fridge manual says cut in voltage is 11.7v which I assume means it needs that to start)
I ran a direct connection from the battery to the fridge using a 2,5mm cable which is bigger than the installed wiring and got 12.3v at both battery and fridge and it worked.
When I tried it with the engine running and no mains and no direct connection it still didn’t appear to work which seems strange.
So does this mean I need to change the wiring from the fuse board to the fridge?
The van is a Danbury conversion and it seems strange that they would install wiring that is too small so is there something else which could have failed to cause these symptoms. The fridge used to work ok on 12v and it’s a new leisure battery.
All very puzzling!

 

[AussieMick]

Possibly a loose connection in wiring to fridge as when you used a jumper cable it worked.
If it used to work the existing wiring must have been adequate but something has changed, ie loose connection etc.
Have you added anything to that circuit.
Have a careful look and you may discover something.
11.5v is too low to run the fridge as you stated
12.3v at battery and 11.5v at fridge is a big voltage drop.

 

[Handypete]

Possibly a loose connection in wiring to fridge as when you used a jumper cable it worked.
If it used to work the existing wiring must have been adequate but something has changed, ie loose connection etc.
Have you added anything to that circuit.
Have a careful look and you may discover something.
11.5v is too low to run the fridge as you stated
12.3v at battery and 11.5v at fridge is a big voltage drop.

I will have a look . The only electrical work done recently has been a towbar and electrics fitted and changing to LED headlights.
Wouldn’t have thought the lights would be involved. Not sure about whether the towbar electrics would change things?

 

[DXX]

You don’t mention what gauge the fixed cable is or if you have checked connections are full core and tight.
It would seem there is too much resistance, either too small cross section, too long (positive & negative) or poor connections, also possibly a combination.
Not sure how long you’ve had this system running but maybe it was borderline and now the leisure battery performance is dropping off.
IMO do the easiest things first;
1. Check connections are full cross section and tight.
2. Make sure no other consumer has been spurred off the fridge cabling.
3. If not already done install a local ground to keep the cabling as short as possible.
Here’s a link to calculate DC voltage drops and other good 12v info’.

Cable Size Calculator - Cable sizing and selection | 12 Volt Planet

Cable Size Calculator - Read our guide to selecting cable of the correct type and size for your automotive, marine or leisure wiring application. Auto and Marine Electrical Components from 12 Volt Planet

www.12voltplanet.co.uk

 

[t0mb0]

Thanks for the replies.
On further investigation
With mains connected 13.6 v at fridge
12.3v at battery with mains connected
With mains disconnected 12.3v at battery and 11.5v at fridge ( fridge manual says cut in voltage is 11.7v which I assume means it needs that to start)
I ran a direct connection from the battery to the fridge using a 2,5mm cable which is bigger than the installed wiring and got 12.3v at both battery and fridge and it worked.
When I tried it with the engine running and no mains and no direct connection it still didn’t appear to work which seems strange.
So does this mean I need to change the wiring from the fuse board to the fridge?
The van is a Danbury conversion and it seems strange that they would install wiring that is too small so is there something else which could have failed to cause these symptoms. The fridge used to work ok on 12v and it’s a new leisure battery.
All very puzzling!

In addition to the cabling voltage drop issue, if you have 12.3v at the battery and 13.6v at the fridge with mains connected, it implies your mains charger (I assume you have one if it's reading 13.6v at the fridge), isn't hooked up to your battery properly. I would guess this is why you are just seeing a problem, some of your recent electrical work has somehow removed the mains charger to battery connection, your leisure battery is no longer properly charged and the resulting low battery voltage (along with the significant voltage drop caused by the issues @DXX explains above) caused the voltage at the fridge to drop below the point at which the fridge functions properly. If this is the case, you need to fix the mains charger connection to the battery and go through the steps @DXX outlines above.

 

[Handypete]

Thanks all for the replies.
The supply cable looks to be either 1.5mm or 1mm not sure. I will check all the connections and see where it leads me. The battery is being kept charged as it hasn’t dropped over the winter whilst plugged in but as observed the voltage at the fridge and at the battery are different on mains.
As you can probably tell I’m no electrician it’s mostly witchcraft to me!

 

[AussieMick]

Dont forget also you can have a battery that is starting to fail that has 12.5v or so with no load but as soon as you put it under load ,ie the fridge starting up it will drop to 10v to 11v or so and it's not enough to run these devices.
If your battery has been on a charger for a long time I would expect it to be higher than 12.3v.

 

[DXX]

I suggest fully charging the leisure battery and then visiting a battery specialist who can load test the battery for a small charge or maybe even free. Make it clear beforehand that you are not in the market for a new battery.
It sounds like a combination of the battery and wiring. Was it a professional conversion?

 

[airhoguk]

It’s possible that the tow bar fitter may have tapped into your fridge supply when installing your tow bar wiring or disturbed it when installing. As well as a loose connection or possibly a bad earth the other consideration is that part of your wiring may have corroded on the surface at a terminal and that has increased circuit resistance​

 

[Handypete]

Firstly thanks for all the suggestions,all very helpful.
I checked all the wiring I could get to , checking all the connections were tight and likewise any crimped connections. I found a main 40 amp fuse that had partially melted but not blown so I replaced that. (Not sure if it effected the fridge circuit) Other than that I didn’t find anything obvious.
When I checked the voltage at the battery, fuse board and fridge it was now the same at all three points and the fridge worked without the van being plugged into the mains.
I left in on battery for 12 hours and the temperature dropped to 5 degrees and stayed there so it seems to be working.
However I observed that the compressor only ran for 5 seconds or so at a time and the fan ran continuously. The flashing single red light signifying insufficient voltage was showing whenever the compressor stopped. So I don’t know if that’s normal or not and I haven’t noticed it before. I can’t see why the voltage would fluctuate when the van is sat there and nothing is being touched?
comments welcome!

 

[t0mb0]

Compressors don’t run continuously, they do cycle. However, the cycle is usually measured in minutes, not every five seconds.

It could possibly pulse like that if the voltage is borderline. The fridge would switch on, draw current, which would cause the voltage to dip below the threshold, which would turn it off, which would allow the voltage to recover, and repeat....

Was it doing that on a full battery, or just after 12 hours or so? What was the measured voltage?

 

[Handypete]

Compressors don’t run continuously, they do cycle. However, the cycle is usually measured in minutes, not every five seconds.

It could possibly pulse like that if the voltage is borderline. The fridge would switch on, draw current, which would cause the voltage to dip below the threshold, which would turn it off, which would allow the voltage to recover, and repeat....

Was it doing that on a full battery, or just after 12 hours or so? What was the measured voltage?

Battery was fully charged and was reading 12.6v at the start which fell to 12.25 after 22 hours

 

[t0mb0]

Battery was fully charged and was reading 12.6v at the start which fell to 12.25 after 22 hours

I would say 12.25v is a bit borderline to be running a fridge from, it might cause the behaviour you saw and it won’t do the battery any good to run it down too low.

I would check if it’s still doing the weird cycling thing with a full battery, if not, that’s pretty conclusive.

 

[Handypete]

I would say 12.25v is a bit borderline to be running a fridge from, it might cause the behaviour you saw and it won’t do the battery any good to run it down too low.

I would check if it’s still doing the weird cycling thing with a full battery, if not, that’s pretty conclusive.

The battery was fully charged to start with the charger had a green light on it signifying it was fully charged. The cycling was happening right from the start as soon as I put it on battery only

 

[Pete C]

Sounds like your leisure battery could be on the way out maybe.
What charger are you using ?

Pete