And off we go...but then no 12v (1 Viewer)

[TrailMix]

Long time reader, first time poster. Very grateful for the wealth of information available and the very pleasant "tone" here - it feels just like a good campsite.

We sold our Mercedes Vito 2+2 pop roof conversion due to lack of room (I am 6 5) and the arrival of our second dog. Delighted to have found a low mileage and very well cared for Auto Trail Cheyenne 634L on a 2001 Fiat chassis. Perfect in all respects for our needs and budget. More power would be great after the Vito - but just remembering we can both stand up at once makes that thought vanish. Good shakedown run this past weekend and the 12v packed up. Nothing at the panel. Zig charger giving output, batteries metered and ok. Checked battery fuse at the rear, all three at the front. All intact. Can't easily check the operation of the (original) split charge relays but from the schematics not sure that would be render us 12v-less. I can read a schematic and use a meter - but time to admit a happy defeat as we planned on a couple of electrical changes, USB sockets in the rear and glovebox, rewire the radio from the leisure battery etc etc...

So - can anyone recommend a mobile electrician in the Warwickshire area - Stratford Upon Avon to be precise? Google is a wonderful thing - but recommendations are priceless.

Thank you in advance for any wisdom shared.

 

[Minxy]

Have you checked the hab fuses, not just the battery ones? Sometimes simply taking them out and putting them back in can sort an issue with one not making proper contact. Failing that can you take the control panel off the wall and get to the wires behind to check if there is anything actually getting to the panel, if so this could indicate that the panel itself has died.

 

[TrailMix]

Thanks Minxy Girl

On this build there are no hab fuses - they have resetable switches on the control panel to manage pump, aux, lights etc. It has all worked until we put it all into "proper use" - my money is on some "post-build" shenanigans that I can't trace...

Time for someone with a Degree in patience and a multimeter!

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[pappajohn]

Most, if not all, British vans still use the ridiculous idea of a relay to cut hab power when the engine is started.
If the relay has jammed open in the N/O (engine running) position you won't get any 12v power... Engine running or not. The relay needs to close when the ignition is turned off to complete the circuit.
The relay could be anywhere but most likely near the mains charger/12v fuse block or near the battery.
It's about the only thing which can kill ALL 12v power at once if the fuses are OK. .

 

[Minxy]

I'm just wondering if you have a bad connection somewhere as it seems weird that everything seems to check out okay yet you have no power at the control panel ... check all connectors are fully pushed/joined together in case one has come lose, have a shuftie under the cab seats as some can 'hide' under there!

 

[Dorset Diver]

This could be way off beam but we have a 12v failure on our AT. It turned out to be a problem with a box situated to the right just behind the drivers seat. Our AT leaked and it had got wet .

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[Spriddler]

I spent many hours trying to cure no power to my Zig panel. All (spade type) fuses when removed checked out o.k. visually and on a meter. Likewise the hab battery, relays etc. To cut a long frustrating story short it transpired that when the fuse was replaced in its holder its contact 'legs' moved just enough to make the fuse faulty, i.e. go open circuit.

 

[TrailMix]

And to close this off (and for anyone else googling whilst pulling their hair out.....) it's fixed. Thanks for the comments and views, pappajohn you got me thinking.

Somewhat at my wits end I removed the control panel above the door and there was the relay for the "no 12v when ignition on". As I touched the relay the earth lead literally fell out. Disassembled and reassembled and I had power to the board.

Happy days. So I thought.

By this point I had unclipped the cable ties for the loom around the leisure battery and so tidied and reclipped it neatly. Power lost again.

Some head scratching later and with a meter located a failing joint at the quick release connector joining the leisure battery feed to the loom. Over the years I guess it had been cable tied a bit harshly with no regard for strain relief. I modified this setup to bring the cables into the bed box where I have used a fresh fuse holder. No more lying on my back in the dark and wet to check the main 20a feed.

So two faults at once making it more fun. That celebration beer tasted better knowing I had avoided the auto electrician's invoice!

Thanks again - the help was invaluable.