RV Repair: Onan Genrator, class c motorhome, fuel pump relay

Question
I have a class C motorhome with a Chevy chassis and an Onan 4KW Microquiet genarator.  I just had the fuel pump module, fuel pump relay and fuel filter replaced.  Now when I run the generator is quits in about 10 minutes.   Sounds like it rund out of fuel.   If I run the engine on the chassis the generator does not quit and keeps running.  Could they have connected something differently when they replaced these parts so that now the generator does not get fuel without the chassis engine running?

Answer
Hi Jim:
Wow, this is a new one! I suppose that the fuel lines could be wrong. The kicker is that the gen set keeps running when you run the main engine. Sort of eliminates everything but the fuel lines. There are normally four lines going to the tank. A main engine feed line from the bottom of the tank, a main engine return line to the top of the tank, a vent line to the top of the tank and the generator feed line about 3/4 way to the bottom of the tank. There is no fuel in the return line unless the engine is running so if the gen set feed line is hooked to that it might run about that long before it runs out? The thing is that there is no reason to splice into that line when replacing the things that were changed. I would run a fuel line from a  gallon bucket, whatever, to the inlet side of the gen set fuel pump. If the gen set runs ok here then the problem is fuel to the gen set. Then if fuel comes out of the line that you took off the pump when you run the main the lines are crossed. Good luck.
Bill