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carlsagan · 03-23-2023, 08:08 PM

I have made a few posts here and appreciate everyone input and expertise. We got through the Brake issues, and the fuel filter seemed to fix our limp mode issues so far. Since I bought this 2000 36 MDDS it has been sketchy electrically. I put new batteries in it, cleaned up the connections and that fixed a lot but right now when I run the generator it does not seem to be charging the house batteries, only when it is plugged in to shore power. The light on the inverter will not come on for charge when we have generator power. Additional a lot of out lets seem to work sometimes off generator and not others. I cant figure out what is going on. The only breakers I know of are in the toilet room. I am searching for an owners manual on the inverter but so far no luck. Can anyone help? Currently, and often dry camping in this coach so the generator not charging batteries is a big problem.

shootist · 03-23-2023, 08:10 PM

Be nice to know what generator. Most have two circuit breakers on them. Maybe one is tripped.

carlsagan · 03-23-2023, 08:36 PM

Good point its a Onan 7500. Runs on diesel, it has one breaker and it is on. I cant see any reason it would charge batteries while plugged in but not off generator. The generator should act identical to the shore power, at least in any RV I have ever dealt with.

shootist · 03-23-2023, 09:09 PM

1 35 amp breaker is 4200 watts. Something is amiss. It must be a double breaker. Trip it and reset it. Even if it resets 1/2 could still be bad. The only other place is your transfer switch has lost a leg. The default is usually to the generator, with it running put a volt meter on each output going to the coach. You should see 120v ac on each one. One of them may go straight to the pass through on the inverter.

carlsagan · 03-23-2023, 09:31 PM

Your describing the little flimsy plastic breaker on the generator itself right? Your saying there should be two there? Makes sense what you are saying. If one leg is lost it could be the leg with the charger on it. When you say one of them may go straight to the pass through on the inverter what do you mean by that? One of the legs out of the inverter?

shootist · 03-23-2023, 09:35 PM

Quote:

Originally Posted by carlsagan

Your describing the little flimsy plastic breaker on the generator itself right? Your saying there should be two there? Makes sense what you are saying. If one leg is lost it could be the leg with the charger on it. When you say one of them may go straight to the pass through on the inverter what do you mean by that? One of the legs out of the inverter?

Did some reading, it’s a double pole 35/35 amp breaker. (I have the same gen) if you have 2 ac’s turn them both on with the gen running, off shore power. They will be on separate legs. If only one fires up we can go from there.

Alpine36 · 03-23-2023, 09:46 PM

Slide the generator out and follow the grey Kellem’s loom exiting the genset back to a 5” grey junction box mounted to the coach. Open it up and check the connections. WRV used wire nuts there, and that area is notorious for bad connections. I almost guarantee you’ll find the problem there. It’s a bit of a wiggle to get in there, so make sure you have an assistant to hand you tools. I eliminated the wire nuts and used quality crimp connectors.
Good Luck.

andy29847 · 03-24-2023, 05:59 AM

What alpine 36 said! That junction box is a trouble spot. Besides that, the charge light on the control panel is actually an on/off button. Press the button and see what happens. Besides that, there is a breaker for the inverter in the AC main panel (labeled inverter). The power panel is a good test point. I'm also curious to about what lights are lit on the inverter. Besides that, the automatic transfer switch is a set of relays in a black box on the ceiling in the rear of the big underneath storage compartment. You can look in there for signs of burnt contacts. The potential trouble spots are also potential hazard spots. Don't let the smoke out or hurt yourself.

carlsagan · 03-24-2023, 09:08 AM

Wow some great info as usual. The two AC thing makes perfect sense to test this theory. I just have to remember how to turn switch zones on the thermostat. It definitely seems like its going to be in that junction box and one entire leg is lost from the generator. That is why some outlets don't work, and the charger doesn't work. Those images are super helpful I saved those off for reference. I assume that diagram with all the small images is alpine specific. Makes me wonder, I have never gotten anything out of my boost switch to link the chassis and house batteries. Maybe the solenoid is just bad. What is the echo charger? And were is the charger that would charge house batteries off shore/gen power?

Alpine36 · 03-24-2023, 09:40 AM

Short answer…
The four 6v house batteries charge via your inverter. (aka inverter/converter combi)
The ECHO charger charges your two grp31 chassis batteries only. ECHO charger “piggybacks” off of the inverter charge output to the two chassis batteries at a much lower charge rate. (15a max)
Both are located under the bedroom closet.
In Andy’s picture above note the inverter control panel.
Both “AC In” and “Charge” button lights must be illuminated before either charger will output anything to either battery bank.

The boost solenoid is a separate issue…

andy29847 · 03-24-2023, 09:58 AM

Quote:

Originally Posted by carlsagan

It definitely seems like its going to be in that junction box and one entire leg is lost from the generator. That is why some outlets don't work, and the charger doesn't work. Those images are super helpful I saved those off for reference. I assume that diagram with all the small images is alpine specific.

The images on the homemade diagram are specific to my Alpine Coach 38 FDDS. Your coach should be the same or nearly the same. The inverter breaker in the main AC panel would be a good test point for your problem. Heck, your problem could be a bad breaker. I left that one out earlier.

andy29847 · 03-24-2023, 11:44 AM

I hoped you are fixed by now or at least know what needs to be fixed. Here is a couple more electrical diagrams. I make/modify these drawings so I understand how things work in my coach. I hope this helps.

edge68474 · 03-24-2023, 12:08 PM

You guys are " The Greatest ".
Hi Mike.

Old Scout · 03-24-2023, 02:27 PM

Didnt read the whole thread but IF everything works on shore power but not on genset, you have a shorter "adventure." If shore power is charging house bats the inverter is working so focus on genset feed. Just like looking for water in a pipe--if there is "blockage," you need to start at one end and check all the options. First--check the 120v on the genset --2 legs 120v each; then check the aforementioned junction box on ceiling above genset; then check in and out at transfer switch, again 2 legs; then breakers in bathroom. Inverter use a by-pass circuit limited to 30 amps, so only some light and plugs [eg, microwave but not the roof A/Cs]. So route from genset to gray breaker box in bath will be your focus.