Fridge 12v - Advice Please

[Johnb]

Mobile engineer noted that the fridge isn't working on 12v. He's unscrewed the fuse-board as shown in pics revealing a "burnt" connection.
I have found the fuse-board and intend getting a replacement assuming there will be damage. (https://sargentltd.co.uk/shop/product/c44-fuse-box/250) .

A few questions. I'm NOT an electrical engineer although do own a multi-meter!

My thoughts are:

A fuse blows for a reason. If I renew the fuse-board and re-fit the wires then exactly the same thing could happen so:-

Step one might be to take car to tow bar fitters and have 13 pin electrics checked. (I think I've read that there are testing kits they just plug into the 13 pin on car so can give me a verdict, as it were, instantly. Hopefully this will eliminate car side issues.

So far as caravan side issues I've no idea where to begin. My fear is that a little knowledge can be very dangerous and I'm concerned that I may cause damage.

If anyone can run me through the things I can do and explain clearly (presume I'm an idiot) I would be grateful. Whilst no 12 v fridge when towing might be no big thing in the UK we will be in Spain later in the year where every bit of cooling matters! I am told by the mobile engineer that the fridge will still operate normally on gas and 240 mains.

Please see pics showing damage. I've not done anything so far - not even checked the fuses.

 

[GaryB]

It could well be a poor connection caused over heating and eventual fuse failure, heat degrades an electrical connection very quickly, the degradation leading to a rapid increase in resistance. Part of my job is to conduct failure investigations on electrical joints (albeit at a much larger/higher voltage than 12 volts) but the majority of failures are either due to water ingress or a poor connection.

I would replace the fuse board but ensure that all connections are good, ensure the terminals are clean and that any plugs engage properly, multi-plugs tend to contain female spade-type connectors so just ensure that they haven't opened up which will give a high resistance connection.

 

[Jcloughie]

You are correct that fuses generally blow for a reason, particularly when the burn like yours has. Good idea to change the fuse board. But I would check the fridge itself. The heater may have failed and shorted.

Search on YouTube for “Dometic fridge element replacement”. (Assuming it is a Dometic fridge)

John

 

[Beardy]

I'm with @GaryB on this. Most likely a bad connection causing over heating. You need to change the plug as well as the board. If you know a friendly electrician they will be able to check the current drawn by the fridge on 12v after the board has been changed and confirm that it is below the fuse rating. It's not difficult to do but probably better to get it checked professionally if you're not confident.

Edit: If you bought one of these you could easily check the current drawn yourself. Just unplug the fuse and plug this in its place.

Car Circuit Fault Finding Auto Current Tester Repair Fuse Leakage Detector Kit | eBay

1 Car Fuse Current Tester. Used to detect the current of a car, fast detection and high accuracy. Maximum Load: 20A/48V DC for 10 seconds. For Latest Model Piston Art Keychain Mini Key Ring Engine Piston Model UK HOT.

www.ebay.co.uk

 

[Johnb]

Thanks for the advice.

John - I have now checked the fuse and its not blown.

I telephoned Sargent who though it was a poor connection Gary and Beardy.

The plug is impossible to disconnect so I expect it has "welded" itself to the board or I'm not able to grip and withdraw effectively. I was able to release others easily.

State of play is new board ordered and set of "plugs" to mach. They were £13.63 but I couldn't find anything elsewhere that was exactly the same as original. Anyway - if sorted for £59.45 plus £13.63 I'm more than happy. Had thoughts of 3 month wait for parts and think of a number and double it for parts!

Again thanks for input. Appreciated.

 

[trevormonty]

Connector has been running hot for quite a while. Either to high current draw for that circuit or maybe poor connection on that particular pin. Need to find out which wire circuit it is.

Make sure each circuit has correct fuse as per manual. Sometimes peoples solution to blowing fuse is to replace it with higher rated one eg replace 5A with 10A.

 

[Buckman]

It is possible that there was condensation on the board and this caused the short.

 

[Dustydog]

Replacing the board is a good call. Use new fuses and spray electrical contact spray into each connection and fuse. Helps etch a better contact.
Do the same with all the multi pin plugs and sockets.
Double check the efficacy of the 12v earth return.
Hopefully all will now be fine

 

[ashleyB]

I've got the same issue. It's not the Fridge 12v +ve, it's the earth return.