'02 LY 26' House Batteries not charging

[kardy]

Hi all, I'm new here and the new owner of an '02 26' Land Yacht. I've become familiar enough with it to at least describe my problem, and have hit what I think are the obvious potential trouble spots, but none of which have solved the issue.

That's why I'm here. The 2 coach batteries will ONLY charge from the alternator on the engine. Neither the genset, shore power or even the solar cells provide any charging to them at all. Obviously the gen. and shore both run through the converter/charger, but is the same true of the solar panels?

I've pulled the existing converter (a WFCO unit, not sure of the precise model and new in 2010) and taken it to a dealer, where they tested it to see if the output was right - they said it was around 13.8v - and said that probably wasn't the issue. I've checked both fuses on the unit, a fuse in the driver's side exterior fuse box (where the power center is) marked as "battery charger" and the fuse that runs on the lone wire coming thru the firewall and connecting to a positive terminal on one of the batteries. All look good.

What else can I check? I've been charging the batteries with an external charger just to pull them out of the danger zone (because, maddeningly, damn near everything in the coach depends on 12v power to operate). I'm trying desperately to not take this to a dealer for diagnosis but I'm at the end of my rope.

Please give me some thoughts.

[kardy]

Well, it looks like I may have "stumped the chumps", as they say on Car Talk...

[Phoenix]

Have you had the batteries load tested? Before you spend more time troubleshooting, I'd make sure that the batteries are OK.

If you haven't already done so, remove both batteries and charge them separately overnight. Then, take them to an autoparts store (Checker/O'Reilly, AutoZone, Pep Boys, etc.) and have them perform a free load test.

If the batteries are severely discharged, a regular charger (including your converter) may not be able to charge them. If necessary, the autoparts store can "fast charge" them for an hour and perform the test again. This should not cost anything, as this is a free service they provide hoping you will buy a new battery from them.

If the batteries are OK, post the results in this thread; and others can provide further troubleshooting tips.

[kardy]

Thanks so much for the reply. The batteries charge up and hold a charge fine with an external charger, and with the alternator, just not with anything that runs through the converter/charger (which supposedly tested fine according to the dealer). Beyond the four fuses I've already checked, I just don't know where else to look for the problem.

[Phoenix]

Some batteries will read OK (i.e., measure 12-12.5 volts) on an open circuit (no load), but will immediately drop to about 10.5 volts or lower when a heavy load is applied, which indicates a defective cell. If you haven't already, I'd still take the batteries to an autoparts store to have them load tested. Their tester draws enough amps to simulate cranking a big V8 engine with every 12-volt accessory you have turned ON, and it will indicate if the batteries are working OK and not just reading a surface charge.

Have you done any repairs to the 12-volt system on your land yacht? If so, I'd double check to see if you may have a loose connection on any of these wires or terminals. Also, if you removed the converter, I'd make sure that all of the wires got hooked up on the right terminals, and that they are securely tightened. (A loose connection can cause symptoms similar to a bad battery.

Otherwise, you may have to have an RV tech troubleshoot this problem. 12-volt systems aren't too difficult to repair, but it's hard to troubleshoot remotely. Without actually being able to probe different circuits on your Airstream, we're just shooting in the dark. Sorry, I can't provide more help from this end.

[kardy]

I took it to a tech, after about an hour he determined there was a 50amp breaker that was bad. He replaced that and now good to go. Thanks for the help, Phoenix.

[woodytwo]

I got a similiar problem. Where do I find this 50 amp breaker?

[Mexray]

Glad you found the problem and are up and running again...

When I incounter this type of problem, I like to play a game I'll call 'Follow the Electrons'...

1. buy an inexpensive digital volt/ohm meter - Harbor Frt sells em' for less than $10 - a handy 'tool' to keep with your stuff...

2. check and note the voltage AT the battery terminals with shore power OFF...

3. Turn ON shore power & AC breaker to the converter/charger - again check and note voltage at the battery terminals - if voltage is elevated, charger is working - if NOT, charger is not working or current isn't reaching batteries...

3A. be sure to check voltage at the cables AND at the battery terminals to see if there is a connection/corrosion problem to eliminate...

4. with voltmeter, check output of charger with power ON to determine if it's working...13-14 volts DC perhaps...

5. next trace the wiring to the fuse panel where the cables from the charger enter - again check DC voltage with meter...

6. If there's an auto circuit breaker at fuse panel at input from charger - check both sides of breaker for charger DC voltage...

7. next check both sides of installed fuses to insure you don't have any 'blown' fuses, or dirty contacts (common in old, round, glass type fuses)...

8. next determine if you have a battery CUT OUT switch - if so, check both sides of switch/relay for charger DC voltage...If you have voltage on the OUTPUT of this switch, you should then have same voltage at battery terminals - if not you'll have to chase the wires to the batteries to find the 'open' circuit - broken wire, corroded connection, etc...

Chase the Electrons - fun game...

You could play this game backwards, starting with the batteries, but I like to start at the voltage generator (converter/charger; trailer harness, etc) and work toward the batteries to find the 'open' in the circuit...

[woodytwo]

Maybe Mexray has a game for my problem?

My coach batteries do not charge from the alternator. Charge ok from shore power. Charge will last 2 days of boondocking. This problem seems to have been there for some time. Bought the M/H a couple of years ago and experienced the problem. Thought that the batteries had had it and replaced them but problem is still there. Any help would be appreciated.

[92landyacht]

Does your chassis battery stay charged while driving down the road?

[woodytwo]

Originally Posted by 92landyacht

Does your chassis battery stay charged while driving down the road?

Aparently not. Haven't checked it out with a meter but I seem to lose the charge whenever I'm not connected to shore power. I have a meter ( well 2 meters) but i'm not the best guy in how to use them. I do not think that it is one of those phathom losses but who knows. From the time that I disconnect from shore power with a fully charged set of house/couch batteries, the available power seems to decrease. So what power do we use going down the road? steps, interior lights, water pump, water heater, etc. when we are parked for the night, of course there is alot of interior lights on as well, including the aisle lights all night plus the outside lights when we need them. so if we then travel down the road the next day, my thinking is that whatever the batteries lost in voltage would be replaced by the alternator charging them as we go down the road. But this does not happen.

[Schools Out]

Woodytwo, you mentioned on another thread that your house & chassis battery switches did not work independently of each other. That's where I would start looking for answers. On our 05 there is no way that using all the juice in the house batteries will drain the chassis battery.

[92landyacht]

Originally Posted by woodytwo

Aparently not. Haven't checked it out with a meter but I seem to lose the charge whenever I'm not connected to shore power.

I don't think you understood my question. I was asking about the chassis battery. Not the coach batteries. Does the battery that is used to start the MH run down when driving? If not, then your alternator is probably still charging. Check the voltage across the chassis battery with the engine not running. Then check it with the engine running and see if the voltage increases. Do the same with the coach batteries and report back with what you find.

[woodytwo]

My apologies. Yes, the chassis battery always is in good charged mode and doesn't lose power as we go down the road.

Also have found out the the battery cutouts switches are working in tandem which they shouldn't be. I'll follow up on this.

Should have some time later this week to check out these suggestions.
Thanks for you feed back.
Woody