I have run into a problem with our 4K Onan genny. It would shut down in places like a traffic jam in the Mojave (Vegas to LA) or driving through the deep South. When we needed it the most it died. I tried all of the adjustments without any luck. I found out that many of them have a temp sen sot in the intake that shuts it down when the ambient air reaches 130f. I have a IF temperature gun so I did some checking. The tarmac often gets to 150f here in S FL. No wonder. I tried leaving the door open a crack and a few other things without much luck. Coachmen, in its infinite wisdom, put the generator behind the drivers side wheel well where the radiator heat washes through it. The intake in the genny box is in the front where it sucks the radiator and engine heat in as well as the brake and tire heat. I read where some folks ran dryer vent hose from the box to in front of the radiator but the suspension and a tight space made it tough and it would still be right on the road. Here is what I did.
I am still in the midst of painting so it is not perfect yet and this is not all of it. The louvers come from a Sea Ray engine compartment and were meant to exhaust. I just turned them around. I cut a hole and screwed them on. I am repainting the lower part of the RV so I am painting them.They were sanded and primed with plastic primer before the color coat went on. I will be spraying the clear later.
I did not block the old intakes to the compartment. I used foam to direct the air flow from these intakes to the intakes on the genny's own case. I'll post more picks in a day or so.
The generator now draws its air from outside of the RV about 3' off of the road. That helps a lot even when standing still in traffic. When moving the scoops direct air through the generator. We spent a few days in Death Vally during August without any problems at all.