Onan Marquis 5500 Problem

[Paul T]

When generator is hot, (having run in the last 30min, and the outside temperature is warm (80+), the generator starts, but does not produce output on the power load meter. If you let the unit cool enough, say an hour in 80+ degree weather, then the unit will start and produce current on the load meter. There seems to be no correlation if there is a load (fans and ac) on the generator at time of startup, and the unit will not produce current even if left on for say 20min in the fault scenario

[Chief]

Not sure I understand the problem correctly. Are you referring to the "one place" power monitor inside the coach or referring to meters that are located on the genset itself? Definately sounds heat related.

I would start by checking the genset output @ the contactor switch in the electrical bay. If output is good @ that point and no input to the RV circuits then the contactor is not functioning properly. If there is no genset output @ the contactor input then start working back towards the genset until you get an output, the problem will be the previous junction that was checked.

[Paul T]

Re. clarification of the problem; when the situation happens there is no AC power to the coach. Nothing is indicated on panel, not power to outlets, and no power to air conditioning units.
I have seen one write up in the systems section which indicated a simular problem was cured by cleaning the "brushes" on the generator but have not been able to check that area yet.