Generator problem 7.5 onan

golfman 1 wrote:
When I put full load on gen it cuts off and throws a 33 code. I checked coolant and air filter as per manual both ok . What could be the problem?

golfman,
Code 33 on many of the 7.5QD Onans is what's labeled an "Overheat" condition. And, in the service and owners manuals, they list possible causes. About 99.99% of which, never are the cause.

1. Plugged cooling air intake
2. Plugged cooling air exhaust
3. Damaged cooling fan

And a few more.


A very large percentage of the time, the actual cause is the "Temp sensor". It's a sensor, located in the lower half of the thermostat housing, in the back (or front, depending on how you look at things) of the engine. Long story short, that sensor can get severely corroded, inside it's pocket in the housing and, cease to send correct signals to the little Kubotas ECM. When that happens, it sends false heating info to that ECM and, the ECM then shuts the engine down, even though it's running at the appropriate temp.

I'm not guaranteeing that this is your issue but, about 80% of the time, it turns out to be it.
Scott