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zduffie · 02-12-2019, 03:09 PM

Good day!
Have an aggravating issue with my Onan 5500 generator, that hopefully someone on here as a solution.

Original problem, would not crank throwing a code 32. Took to a Cummins certified mechanic and had the following work done (drive system rebuilt under warranty, new carb, new rotor, new control board, new pins for switch, new oil and oil filter).. Just a few things.. Now am facing another issue. Unit cranks up well, runs well for a little while under idle, then shuts off. If able to get a load (2 ACs) on it, it will run for about 1 hr. and shut off. If I reduce the load or shut the load off at any point, the generator revs briefly, comes back down and will shut off in about 2 minutes. And unfortunately, the control board is not providing a code, which is stumping us and the mechanic. Help!!

MSHappyCampers · 02-12-2019, 05:42 PM

Welcome to IRV2! We're sure glad you joined the gang!

Sorry I don't have an answer on the generator problem.

Good luck, happy trails, and God bless!

Randalpho · 02-13-2019, 07:08 AM

I had a similar issue with mine shutting off with no load. While monitoring the frequency at any outlet I had 60 Hz with load, shut off the load and the Hz quickly climbed and the genset would shut off. Mine is too old for flash codes so I had nothing to go on outside of I thought it idled higher than it should (1800 RPM). The genset was shutting itself down for safety due the Hz.

I finally figured out that the OP had raised the hard stop on the carb to calm a surging problem. I had previously cleaned the carb which cured the surging. After resetting the hard stop it idled lower and the electronic governor could control the frequency which fixed the shutting off problem. The hard stop should be one turn after contacting a closed throttle plate, it was set at three turns.