'92 Coach Battery Not Charging from Alternator or Shore Powe

[metrogeek]

Thanks Skater for this excellent resource. I'm a Newbie to RVs - excited and nervous all at the same time. Contract work is requiring full time RV life and this is where I am starting.

1992 Airstream B190. I recently replaced the coach battery which was putting out .4 volts but I've noticed that it is not charging from the alternator or shore power. I'm working on the generator so I can't test.

If I crank the engine and run jumper cables from main battery to coach battery the monitor shows it to be charging. As soon as I disconnect the jumper cables - it stops. I followed the cables from the coach battery to a 12v 50a fuse block with terminals and getting 10v (the battery is low) up to both sides of the terminals - whether the engine is running or not.

I've read all the articles you from the forums which has helped me troubleshoot as far as I have, but wanted to reach out for any other suggestions.

[Planck]

Did you pull the fuse(mine is 60 amp) to see if it is okay? Not getting a charge from shore power either is odd. I had to do a lot of studying of the factory wiring diagrams to figure out my problem(posted under electrical). Seems like something is disconnected somewhere for neither system to be charging the house battery.

Good luck.

[metrogeek]

I checked the 60 AMP fuse in the T position (I found that and was hoping my fix would be that easy). I back traced the wires (so far) from the coach battery to the 50 AMP terminal type fuse near the main battery (voltage good on both sides of terminals - but only showing the low voltage from the coach battery).
Checked the charging fuse at the power converter (15 AMP fuse is good).

Just for giggles, ran jumper cables from main battery to coach battery - cranked the engine and monitor shows charging.

I may have to give in and take it to an RV service center because I'm still learning about my new life in the B190.

[skater]

Odd. My first thought was that your converter is bad, and it's not charging from the alternator because either the relay that controls it is bad, or it was never installed/disconnected in the first place. Two separate problems in other words.

But, first, does the coach 12 volt system work okay? Try disconnecting the battery, plugging the van into shore power, and seeing if the lights work. Don't do this for long - the original converters don't like to work without a battery attached. If the lights don't work, I'd say your converter is bad. If your converter is working, and the voltage out is good (at least 13.2), then it could be the bad battery is causing both problems.