Originally Posted by isaac W
That makes sense. I hear nothing when I press the battery boost switch. That gives me somewhere to start. Awesome.
What Bluefinn is referring to is basically a "dual duty" solenoid. In that, is has the ability to perform two operations, independent of each other. In one op, it links both sets of batteries, house and chassis, together so that if and when your chassis batteries are too weak to turn that diesel engine over for starting, you get help from the house batteries. That solenoid will manually close, when you push the "Auxiliary Boost" switch on the dash.
The second op is, through the specific wiring, it automatically closes when the engine is running and, then it will send some of the charging current to the house batteries.
1. Does your coach/chassis/charging system have this particular solenoid?
2. If it does have it, where is it, and is it performing as it should?
3. Can it malfunction? If so, how does it malfunction and, how often?
Well, first off, yep, you'll have to determine IF your coach/chassis is equipped with this type of system. I'm not familiar with your make/model/year of coach so, I can't help there. You see, there's all kinds of charging link-up systems out there that link the house batteries to the engine charging system. So, the smart thing do here is, either get out the books on your coach/chassis and find what you have or, call your MFG and or chassis maker and see if maybe they can help.
Now, if you do have it, then where is it so that so you find it and begin a test or two to see if it's functioning as it's supposed to, in both operations.
And, speaking of that, does it malfunction? Yep, it sure does. And, based on a few threads on this forum and, a few on other RV forums, it has a somewhat reputation for foul-up. How often does this happen? Well, on some coaches/chassis', like ours, an '04 Itasca Horizon 36GD with the C-7 330HP CAT, with 65K on the clock, it's only happened once in 11 years. And the symptoms were exactly what you're presently experiencing, no house battery charging while driving down the road.
Can it be fixed? Well, yes, it depends. Inside those solenoids are a set of contacts. They are heavy duty contacts that, over time, and, hundreds and hundreds of cycles, can get "arc burn" on them. When that happens, you get a sort of carbon between the contacts and that results in a "NO-Contact" between them. When that happens, you've lost your ability to utilize the house batteries as help when you need them.
And, it looses its other and, most needed function too. And that's the ability for you have your house batteries being charged, when your engine is running. So, can it be fixed you ask? Most gents on here won't bother. They'll simply go purchase another one and install it and call it a day. But, me being me, I like to see how things work. So, I dissected mine. It's simple. I drilled the rivets out that held it together. It pops open to reveal the working parts and, the tarnished contacts.
Well, with a bit of work, a dremel, some sand paper, and, some small screws to put it all back together and, it's been working like new for a good couple of years now. I check the voltage at the batteries every so often to make sure, while the engine is running.
So, sorry for the long explanation but, I thought you'd like to know how things work, if you have this kind of system on board your coach.
That is one type of battery link/charging system. As stated, there's plenty more of them.
And, if and when you find out, just what kind of system you have, and, get it fixed, if I were you, I'd check the actual output of the alternator, at the house batteries, when the engine is running, on a somewhat frequent basis. That way, you'll know for sure, just what kind of voltage is actually getting to both your chassis and house batteries.
Its one of those things that, while I use the inside panel on battery checks, I also use my volt-ohm meter right at the battery posts (of all batteries) to see just what's getting to them. Good luck.