Fridge/Freezer

pamjon

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Hi,
I have just switched my fridge onto the 12volt (engine on) and it is making a loud brrr-ing noise, and lights are flashing red. It works ok on gas and mains. It is a large fridge-freezer with a large freezer compartment.
Any ideas on what the fault can be.
PJ
 
Make Model & year of fridge would help.

So would a video because sometimes sounds & lights contain an error code.

At the risk of being thrown out of the group .... have you looked in the manual.

When you say "engine on" do you mean "ignition on" or "engine running" ?
 
Make Model & year of fridge would help.

So would a video because sometimes sounds & lights contain an error code.

At the risk of being thrown out of the group .... have you looked in the manual.

When you say "engine on" do you mean "ignition on" or "engine running" ?
The fridge is a Dometic, model is either a RM7601L or RM7605L I say either as the booklet says the 2 model numbers. The Motor Home is a 2004 Burtstner T615. I tend to think it is either a relay or something wrong with the brain. The fridge/freezer is an automatic. So when it switches to 12volt when switchiing the engine on (running) that is when it makes the loud noise. Working on gas and mains.
Grateful for any help and or suggestions.
PJ
 
The 7 series fridges were prone to faults in the printed circuit boards behind the front fascia. Get an auto electrician to check them out. New PCBs are no longer available so if one is proven to be faulty search for companies that can repair old ones.
 
The fridge is a Dometic, model is either a RM7601L or RM7605L I say either as the booklet says the 2 model numbers.

There should be a label inside the fridge with the model and serial number on it. You may need these if you are getting spares.

Did you look in the manual to see if the flashing lights are an error code?

Sounds to me like a problem with the 12v cooling system in the fridge. Possibly the motor which shouldn't be too expensive.
If you post a video of the lights, as requested, make sure the audio is on so we can listen to the noise.

As a temp measure turn the temp down whilst on gas/EHU and off during travel. We have been without 12v for up to 36h on the long (via France) ferry to Spain with no problem.
 
If it works on gas and electricity it is a absorption fridge and doesn't have a motor
The noise could be a relay switching on and off very quickly. Could be a faulty thermostat.
 
Thank you to everyone for all the ideas, please keep them coming in as they are very useful.
PJ
 
Unless you have a massive battery bank this will flatten the battery in a very short time.

A typical 3 way fridge is 335w which is 1.5 amps @ 230v
This will draw about 30 amps from the 12v battery

A 120 ah battery will, therefore, be flat in 2 hours. :(
A typical 3-way fridge is actually more like 200-220W and once down to temp, has an on/off duty cycle which means the average power draw is around 75% of that.

The principle of your post is valid though.
 
Yes, I wasn't clear enough.
What I mean to say is that instead of running the fridge on 12v. you could run it on 230 v. through an inverted whilst driving. No point in doing this when you are parked. Then you run your fridge on gas, which works even better, and doesn't use any electricity.
 
Take the bottom vent cover off and undo all the connections and spray with WD40 before reconnecting them, I had a similar issue a couple of years ago and this cured mine (y)
 
I had the similar fault as Jeff a few months back and done exactly the same with the electrical blocks etc and it's never hickupped since🤞
 
Will give it go with spraying with WD40 on the connections as soon as the weather is kinder. Thanks.
PJ
 
99% certain this'll be a bad connection somewhere. It could be anywhere including the -ve supply line. Try all the connections/junctions/fuse holders etc starting at the main battery and work your way along doing the easy accessible stuff first. Make sure screw terminals are clean and tight.
Rather than simply spray spade terminals with WD40 I suggest you also pull them apart several times and make sure they are a tight and clean them with Emery if need be. You're looking especially for the main power wiring which will be substantially thicker than other lower power cables and interconnects. Good luck!
 
Still stuck in Hertfordshire but I hope to be home in a few weeks John, I will give you a call and pop round, it will be easier with two of us ;)
 

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