Generator does not charge house batteries

[whataboutbob]

Ok I have a 1997 coachmen catalina. The generator does not charge the house batteries or power anything in the motorhome. It does run the ac when on. and shore power everything works as it should. I have looked everywhere but behind the Magnetek converter for the ats. So is this where its at?

[Gary RVRoamer]

If the a/c works via the genset, then the transfer switch is working ok. It sounds more like your battery(s) and/or converter/charger are offline or broken some how. That's where the 12v power comes from, whether on genset or shore power.

Is this a 30A RV, or 50A? One a/c or two? If two, do both a/c run via genset? I ask because there are wiring differences that may affect the diagnosis.

To answer your question, the ATS is probably behind the Magnetek - that is a common location. It will be wherever the genset and shore power cord come together, and the usual locations are (1) in the compartment where the shore cord enters the coach, or (2) behind the 120vac load center (breaker panel).

[FreedomDream]

There is a circuit breaker on the generator. You have blown that breaker. Re set the breaker on the generator, make sure all the appliances are off (in other words remove the load from the generator), start the generator and let it come up to operating temperature. The first thing that will come on automatically will be the charger (there may be up to a two minute delay before the charger comes on if you have a surge guard). After that is on, you can start to put a load on the generator.

[whataboutbob]

nope it not the breakers on the generator checked them they are both on and putting out 120. that is one of the things I checked before I posted.

[whataboutbob]

Its a 30 amp. And you can only run one Ac at a time on generator.

[whataboutbob]

Batteries were replaced lase year. So its got to be the ats or the converter/charger. but as you know you have to check everything first be for replacing parts. Or you will just be spending money where its not needed to be spent.

[Mich F]

Unless someone added an automatic transfer switch, that Catalina probably doesn't have one (my 1997 Catalina didn't have one). I had to plug the shore power cord into a 30A receptacle in the same enclosure the shore power cord comes from, to get generator power to the house.


In reading the OP, I missed the part where the generator powers the air conditioner. I guess it has an ATS - disregard my post.

[nothermark]

As was said, the generator feeds AC to the house that in turn feeds the converter and the A/C's. If the Air conditioner compressors turn on you have AC power out of the generator.

Given the year did you buy it new or recently acquire it? It sounds like somebody might have changed the wiring so they could run the A/C without running the house. I'd start by checking the AC input to the converter and working backwards to the panel and then transfer switch. You can also do most of that with the power off using a continuity checker/ohm meter.

The reason I can see that done is to run the A/C off the generator when driving and charging the battery from the engine alternator instead of the converter.

[whataboutbob]

I recently acquire it. It does run the A/C off the generator when driving but not charging the batteries. the House batteries do charge when driving it. where is the AC input to the converter. That is why I think the ats is not working right.

[FreedomDream]

Originally Posted by whataboutbob

I recently acquire it. It does run the A/C off the generator when driving but not charging the batteries. the House batteries do charge when driving it. where is the AC input to the converter. That is why I think the ats is not working right.

I am suspecting the ATS now, too. If you can access The ATS, plug into shore power and give the ATS box a good wrap with the handle of a big screw driver to help free up the stuck switch. If you can remove the cover of the ATS you can use an electrical lubricant like CRC 2-26 on the hinge points of the switch and plug into shore power then start the generator to make it switch. Good luck.

[whataboutbob]

Yes but where is the ast at? And if its behind the converter box a good wrap with the handle of a big screw driver will be kind of hard to do. And I'm looking behind the converter box today.

[FreedomDream]

Originally Posted by whataboutbob

Yes but where is the ast at? And if its behind the converter box a good wrap with the handle of a big screw driver will be kind of hard to do. And I'm looking behind the converter box today.

Follow the electrical cord from the outside into the coach. It should be a gray box or black box BEFORE the inverter. You can do the same with the generator power cord. It, too, will be before the inverter.

[Mich F]

Originally Posted by whataboutbob

I recently acquire it. It does run the A/C off the generator when driving but not charging the batteries. the House batteries do charge when driving it. where is the AC input to the converter. That is why I think the ats is not working right.

What size/model Catalina do you have ? Is your house battery switch turned off ? The alternator on your MH engine should be charging the battery while you're driving.

You said the house batteries DO charge while driving. In my mind I read DON'T charge while driving. I better quit replying to this thread.
Oh wait, I just read it again. You said the house batteries don't charge while driving and they do charge while driving - which is it ?

[whataboutbob]

Well I found the ats and with the generator running I have power to the black wire and not the white. So I'm thinking its the converter. Its original so its time to up grade.