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No power from Alternator to Leisure batteries.

Posted: 11 Dec 2023, 14:46
by Porkscratching
This is really effecting my ability to fire up the Erber. The alternator is giving a healthy output but it's not reaching the leisure batteries which are in reasonable health. If I hook up to the mains I get 14+ volts at both cranking and leisure batteries.
I've taken the BBB apart and the only thing I can see amiss is scorching on the PCB around one of the diodes.
Is it likely that this is the culprit or should I be looking elsewhere?

I was away recently in subzero temperatures. With the engine running the Erber would fire up a treat and then run healthily on the leisure batteries. This is no longer the case.

Help and assistance would be most appreciated. TIA Max.Image

Re: No power from Alternator to Leisure batteries.

Posted: 12 Dec 2023, 08:45
by slowcoach
Hiya,
Since you've got easy access to that blackened resistor, try measuring that for continuity with a meter. It should have some both ways (doesn't look like a diode, unless I'm wrong).

I don't know about those chargers though, but that's an easy start



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Re: No power from Alternator to Leisure batteries.

Posted: 12 Dec 2023, 08:50
by cobblers
Those single layer cardboard/fiber PCBs with big hot components on are an absolute nightmare for getting dry solder joints.
Get a magnifier and flip the board over, inspect the joints near large or hot components in particular and you will likely see a "ring" where the component leg is rattling round inside the joint.

Re: No power from Alternator to Leisure batteries.

Posted: 12 Dec 2023, 10:20
by Cecil
How I see it the mains charging is working so is there a relay or fuses to do with split charging from the alternator that are at fault?

Re: No power from Alternator to Leisure batteries.

Posted: 12 Dec 2023, 15:28
by Porkscratching
Cecil wrote: 12 Dec 2023, 10:20 How I see it the mains charging is working so is there a relay or fuses to do with split charging from the alternator that are at fault?

This is the route I'm going down.

Thanks for the response folks.
I'll post my results.

Re: No power from Alternator to Leisure batteries.

Posted: 12 Dec 2023, 17:33
by Porkscratching
Well folks I'm still open to suggestions.

I've replaced what I think is the split charge relay with a new one and things are the same, ie not working.

Re: No power from Alternator to Leisure batteries.

Posted: 12 Dec 2023, 21:16
by slowcoach
You can do a lot of problem solving with a multi meter, have you got one?

Finding where the power stops for example. alt to charger? alt to split charge relay? relay to leisure battery? etc..

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Re: No power from Alternator to Leisure batteries.

Posted: 12 Dec 2023, 21:44
by Porkscratching
slowcoach wrote: 12 Dec 2023, 21:16 You can do a lot of problem solving with a multi meter, have you got one?

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I have got one although I'm not all that proficient or confident with one.
I don't know where today has gone but I'll be right at it again tomorrow. Starting in the engine bay.

Re: No power from Alternator to Leisure batteries.

Posted: 12 Dec 2023, 22:23
by Mocki
Get your multimeter and take a reading of the leisure battery voltage at the leisure battery poles , the start the engine and take another reading at the place , this will tell you what charge voltage is getting to the battery when the engine is running

Then take a voltage reading at the eberspacher itself and compare the difference .

Re: No power from Alternator to Leisure batteries.

Posted: 13 Dec 2023, 15:10
by Porkscratching
I've taken it to an auto spark. There is no power getting to the leisure batteries when the engine is running the only power is via the hook-up transformer.

I took it to the sparky as I couldn't get any live at the relay under the bench. The sparky doesn't think that that relay has anything to do with the Leisure Charging system.

So the next question is; is there another split charge relay buried within the wiring loom? I've had the interior out in the past and I don't recall seeing another relay but I'm open to corrections.

The junction box in the engine bay has three hefty common Lives running out and away. Is it possible that one of these is a direct feed to the leisure batteries and has developed a break?

Thanks for the input so far.

Re: No power from Alternator to Leisure batteries.

Posted: 13 Dec 2023, 16:12
by shepster
Why not just fit a Voltage sensing relay to your existing setup, or a B2B if funds allow, and use the existing system when on hook up.

Re: No power from Alternator to Leisure batteries.

Posted: 13 Dec 2023, 16:26
by Porkscratching
I think I've got to the bottom of this one. I've found the culprit under the driver's seat.

I'll post results.

Re: No power from Alternator to Leisure batteries. SORTED

Posted: 15 Dec 2023, 15:16
by Porkscratching
Thanks club 80. With a little persistence and help and importantly support from the club we got there. A £5 generic relay was all it took in the end.

Max shall go to the ball, ferry booked. Thank you Club 80-90.

Re: No power from Alternator to Leisure batteries.

Posted: 16 Dec 2023, 09:27
by slowcoach


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