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Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 14897
Experience:  Certified on Onan and Generac generators
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I have an Onan Marquis 7000 in my race car trailer. Was

Customer Question

I have an Onan Marquis 7000 in my race car trailer. Was working fine for years, and 2 weeks ago it smoked the living quarters inverter and a 12v automotive battery charger. I started checking voltage, 155v at the same engine RPM as has been typical forever. I lowered the idle a bit, got the voltage to about 130v, and it would run for 5 minutes or so and shut down. I reset the RPM to where it's been forever, and still multiple shutdowns after 15 seconds to 5 minutes. Last weekend at the track I suspected another damaged automotive battery charger, so I unplugged all accessories and started checking voltage again. Nothing. I now have zero power output. Breakers were not tripped. The confines of the generator make working on it difficult. But I rely heavily on it at the track. I need to know where to go from here.
Submitted: 1 year ago.
Category: Small Engine
Expert:  Hank F. replied 1 year ago.

What is the model number?

Customer: replied 1 year ago.
Expert:  Hank F. replied 1 year ago.


Fortunately, this is one of the easiest Onans there is to work on.

The first thing you need to do is to connect a frequency meter to the output of the genset.

Start it up and note the frequency.

What frequency do you get?

Customer: replied 1 year ago.
I'm at the race track today, when I'm back home I'll get on that. Thanks.
Expert:  Hank F. replied 1 year ago.


I was at the shooting range today. Hope your day went as good as mine.