Sorry, Another Fridge Question!

StitchUp

StitchUp

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Just started!
Our fridge worked faultlessly on gas while at Newbury Showground for the 4 days - it always works well on gas but not at all on hook-up.

The fridge is a
1684856512758.png

1684857158115.png


Here's picture through the side vent - I'm guessing the light blue thing is the igniter which is obviously working fine but, as for the other items in the picture, I've no idea! Is there a relay in this picture - I have a relay checking tool?
1684856415270.png

Can anyone suggest what I should check or maybe do to give things a chance? I have a test meter but don't know what I should expect to 'see' where!

In short, works on gas, but neither on 12v or mains.

I will of course be mindful that when on hook-up there are risks!

Thanks
 
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Maybe worth starting with undoing the very rusty nut and cleaning all the wires and the thread and finding a new nut,spray the rust with penetrative oil a day before you start to undo it
 
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If it still does not work on 230v / 12v after you have cleaned up the ground connections as has been suggested , there are 2 x fuses on the power control module PCB that is fitted behind the fridge control panel on the top of the fridge which may be worth checking (with mains disconnected) .
 
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The gas burner will be in one corner. Going up from it will be a kind of big metal can, containing rockwool insulation. The 240V mains element and the 12V element will be inside that can somewhere. You can probably see the two pairs of wires going to them.

If you can trace them back to a connection block, you can disconnect one of the wires and measure the resistance of the element. Disconnect the hookup cable for safety when you do this.

The 240V element is 220W, so its resistance should be 240 ohms. If it's a lot less or a lot more, then the element has failed, and you need a new one. They are reasonably easy to replace, if you can get to that area of the fridge at the back.

The 12V element is 175W, so its resistance is about 0.8 ohms. This is very near the lowest resistance that an average multimeter can measure. If it's much higher than that, then it has failed. You should be able to tell with a standard multimeter if the resistance is too low. If the meter hasn't got an auto-zero, then before you measure the element, touch the two probes together and read the resistance. That's the resistance of the probe leads, so subtract that from the reading when you measure the element to get its true resistance,
 
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I disassembled the 4 earth connections and removed all the rust with a wire brush attached to my Dremel, checked the continuity to earth and all was good :) Reassembled, reconnected hook-up, checked for 230v supply to the fridge, switched the fridge on but alas, no joy!

So, I removed the fridge front panel but not been able to remove power control module PCB that is fitted behind the fridge control panel on the top of the fridge yet! Looks like I might have to remove the floor of the cupboard above to get to it! Next task :)

Thanks for all the help, much appreciated. :)

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Landy Andy said:
Assume you have checked that you have 240v at the fridge socket, connector?
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Yes indeedy :) All good. I guess the supply at the switch/socket isn't dependent on the fuses behind the control panel top of the fridge? If it was, there'd be no point getting access to it?
I also checked for 12v on the heavy feeds to the connector block - all good.
 
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can you check to see if you have 240 going to the element ,please note there are 2 elements and the other one will be 12 volts so make sure you test the correct one ,if you have 240 at the element leads ,it will def be a faulty element
 
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Be cautious of pulling bits apart at random to check, you can confuse the original fault with a new on you created. Probability is that it's the element failed
 
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i agree .you dont need to pull anything apart just take cover of electrical box at rear of fridge and you will be able to trace the wires and check in the connector block

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when you have removed the fridge control panel there should be 2 x more screws which when removed allow a tray to slide out which has the pcb fixed on it with 3 x screws .
The fuses on the pcb are linked to fridge electrical function.
 
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The unit hadn't been assembled correctly so it was somewhat larger in height than it would have been if assembled correctly, that's why it wouldn't come through the gap!!

Anyway, both fuses are in good nic and I have mains where it should be:
1684939446545.png


While apart any other checks I should make? :)
 
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The AC output to the 230v heater element , when turned on , should be there , but I do not know if it is marked as such but could be marked T6 + T5
As has been suggested and described by autorouter ,have you checked that the heater elements 230v + 12v are ok ?
There should also be a relay linked to the 12v heater element operation on the rear of the fridge.
 
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GeoffnDee said:
The AC output to the 230v heater element , when turned on , should be there , but I do not know if it is marked as such but could be marked T6 + T5
As has been suggested and described by autorouter ,have you checked that the heater elements 230v + 12v are ok ?
Click to expand...
That's one thing I haven't done yet! Will I be able to test from the control board still removed, perhaps across the AC Heater terminals & 12v Heater terminal & earth? If so, as I'd be measuring resistance/impedance would it have to be powered?
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So grateful for all the help :)
 
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You must disconnect the mains supply before following the autorouter instructions for testing the elements (reply 4 ). The 12v element needs to be checked near the metal heating tube on the rear of the fridge as the relay fitted is between the 12v element and the pcb.
 
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StitchUp said:
If so, as I'd be measuring resistance/impedance would it have to be powered?
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No definitely not. The small amount of voltage and power required to measure a resistance comes from the battery inside the meter. It feeds a known (small) current into it, measures the resulting voltage and calculates the resistance. If the circuit is powered that interferes with the measurement, and you get a nonsense reading. That's why I said disconnect it at the terminal block. But it's sufficient to just disconnect one end of a resistance to measure it.

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Just measured the resistance of the element
1685001406889.jpeg

These connectors are marked AC Heater and travel down to the connections on the heater.
I presume when the van is on hook-up I should see 240v between the terminals.

Looking at the heater housing it seems evident that it's been messed with before!
1685001860069.jpeg

I'm including pictures as I hope they might help others as clueless as me :)
 
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That looks about right for a mains heater element. Next thing is to see if the 240V supply is reaching it. With great care, obviously, as it's 240V.
 
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autorouter said:
That looks about right for a mains heater element. Next thing is to see if the 240V supply is reaching it. With great care, obviously, as it's 240V.
Click to expand...
I'm guessing the 240v will be fed from the two pins on the control board marked AC Heater. Gonna check that now :) I'm always careful of electricity
I placed my probes on these two pins, switched the AES button, two loud 'clunks' and the AES LED displayed red. There was no movement on the volt meter display! If the gas had been switched on the fridge would have worked. I'm left wondering if the control board is the problem, doesn't enable a 240v to the two pins marked AC Heater - perhaps a relay issue.
 
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If you are certain that the glass fuses on the pcb are ok (using your test meter) and that the ground connections are all ok , including the one on the pcb , it looks like the control module/pcb may be faulty with the auto select function only allowing gas operation (as it also does if the supply voltage is sensed as being low ).
The relay that is on the rear of the fridge is linked to 12v heating element operation but may be worth checking in case it is faulty and effecting the control module operation
 
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Sadly, you're probably correct!
The two glass fuses are definitely good - I removed and tested them :)
The earth connections are good, nicely cleaned up and tested for earth continuity.
While the engine isn't started I don't expect the the fridge to work on 12v.
I connected my test meter across the AC Heater pins on the control board, switched the fridge on and there wasn't a hint of a 240v presence as I would have expected!
My guess is the AES sequence would be:
1. Mains supply (hook-up) - If present 240v supplied to the heater and fridge works.
2. 12v - if present with sufficient current, fridge will work.
3. Gas - always works on gas :)
At this point I think I'm done but would like to thank all those who've been kind enough to guide me through the testing process :) :)

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I had to walk away from it for a breather :)
I did remove the fuses one at a time to ensure they were clean at the point of contact. I also checked for 12v on the board and found it. Other than that, I left it for a rest :) The fridge now shows no outward signs of life LED etc.
 
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Seems I'll be needing a new replacement 3 way fridge unless I can find a replacement control board :(

The components on the board are half buried in a resin! The only thing left for me to try is resolver the backside of the board in case there's a dry joint.
 
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