House Batteries Not Charging

[grantracy]

While underway my house batteries are not being charged from the engine driven alternator. The batteries do charge when the Genset is running and/or on shore power. The chassis batteries are charging and there is 28+ volts on each pole of the isolator but nothing to the house batteries...any thoughts?

[Joe Cannarozzi]

Tell more. Are they normally always charging while underway or is there a switch you have to throw?

[lloyd&pamela]

I have a 1991 Country Coach and the house batteries are not charged on it from the engine alternator. They only charge from the Gen or shore power. Your newer coach may charge from the alternator.

Set your inverter to shut off if the charge on the house batteries go to 12 volts. Otherwise it takes forever to recharge them and you can damage them if they get too low. Four Lifeline 8Vs are expensive to replace.

Hope this helps some. I am a newbie and Joe is a real expert in these matters.

[dalej]

I think at some point someone changed your guys bus's. The house and chassis batteries should be charging while driving or fast idle.

It just doesn't make any sense that you can't drive during the day and dry camp at night.

[garyde]

Hi Granvil. What makes you believe the engine alternator is not chargng your house batteries? A better question may be why are they not charging now.

[Coloradobus]

Perhaps one of your sacrificial breakers has blown. Our's are called Klixon Breakers, and we find them near the house batteries. They are about 2 in X 3inches in size and have twin terminals on them. We had ours blow in the last coach and the house batteries would only charge by shorepower or genset. just a guess

[grantracy]

I never noticed if they charged by the alternator or not...I got a "low house" light and was told to check the actual voltage on the electrical panel ( which showed 24 v) there is definitely a provision for charging as I have an isolator which splits the charging. I think you may be right about breaker...just cant find it. There is no switch that I know of,looked over schematic which showed a disconnect which I checked.

[JIM KELLER]

Granvil, Usually Jon would be all over this but I know he is busy right now. Yes one of your alternators charges the house batteries. Start at the source and work backwards. Access your house batteries and put a a voltmeter on one of them. Start the Bus with shore power disconnected. Observe readings before starting and after. Do the same thing with shore power. Check all breakers in and around the inverters. Could be as simple as the voltage regulator that is paired up to the alternator has quit or an inverter problem.

Using the proper procedure, you can force the alternator into a full charge at the regulator to determine if the alternator or regulator is bad.

[mike kerley]

Granvil, Follow Jim's advice and I'm sure you'll know a lot more about your electrical system when your done than you did when you started. Seems that no two coaches are exactly alike, and you've got to figure out (or pay a technician to do it for you) just how yours is configured.

Its just a matter of following wires and checking breakers and fuses.

Mine has two alternators, one for the chassis and one for the coach. Not the same voltage output (one 12V, one 24V) . I dont know how yours is designed, but you'll know soon.

Wish I could help more.

[grantracy]

thanks for the help...I have done all of what you have suggested. There is a device in-line called a "cable limiter" nobody seems to know what it does. I am guessing it stops the batteries from back feeding. In any event when the alternator is turning there is 28 volts at the isolator and only 16.5 at the isolator side of the limiter I guess there must be a short somewhere in line.