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Newell Gurus
Strange issue - Printable Version

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+--- Thread: Strange issue (/showthread.php?tid=5799)

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Strange issue - rheavn - 11-20-2020

If I start the engine with the coach not plugged in and genset NOT running, the alternator works properly.

If I start the engine with the coached plugged into a live power pole, the alternator works properly.

If I start the engine and then start the genset, the "check alt" light comes on and no alternator charging is shown on the silverleaf unit.

Any ideas.....................................................

RE: Strange issue - bestgenman - 11-20-2020

I’d look into the alternator on the genset and the series 60 alternator creating an issue .

Not sure what is going on but it only occurs when series 60 and genset running? Right?

If the genset is full fielded and producing max output then the alternator on the series 60 may go to zero output causing the check alt light to come on.

Just my opinion........

RE: Strange issue - rheavn - 11-20-2020

"Not sure what is going on but it only occurs when series 60 and genset running? Right?"


RE: Strange issue - Richard - 11-21-2020

It is either what Gordon says, in that the alternator on the genset is producing enough voltage that the viktagge regulator on the engine alternator thinks it doesn't need to activate. In which case current will be flowing slightly backwards through the ammeter, which will trip the warning light.

Or, the inverter charger is kicking in when you crank the generator, again providing higher voltage than the regulator on the alternator wants. This will cause the ammeter to read backwards. Any chance the batteries are merged?

RE: Strange issue - bikestuff - 11-21-2020

WARNING: DUMB QUESTION AHEAD ....What is the purpose of the alternator on the genset? I can see where it would provide power to the generator itself...but why would it be connected to the rest of the coach? Would one just disconnect it or put big diodes in to avoid this problem?

RE: Strange issue - smagown - 11-21-2020

Doesn't the generator alt supply the coach engine with enough voltage to run , if the engine alt doesn't work?

RE: Strange issue - encantotom - 11-21-2020

i drove over 2000 miles with a non functioning engine alternator and just running the genny. only during the day though. no headlights.


RE: Strange issue - whatsnewell - 11-21-2020

I recently drove about 500 miles with no functioning engine alternator. Having a completely mechanical DD 6v92 engine with o computer helps a lot. Didn't run generator at all. My solar array recharged all the batteries while underway. Just as Tom did, I only drove during the day, but used my headlights for limited durations.

RE: Strange issue - rheavn - 11-21-2020

"Any chance the batteries are merged?"

No  The battery merge switch is not on in either direction and the battery merge warning light is not lit.

RE: Strange issue - Richard - 11-22-2020

I have a couple of ideas that you might try to give more clues.

One, does it make a difference, with the gen running, if you put the main engine on high idle?

Two, as a quick piece of info, can you temporarily remove the fan belt from the gen motor. You don’t want to run it long this way but it will disable the gen motor alternator.

Can you get your voltmeter probe on the back side of the alternator and read the voltage with the engine running?