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coventryhale · 07-21-2014, 01:45 PM

Unit runs approx 30 seconds and then quits, showing code 33. Have replaced oil, oil filter, air filter and have a half tank of diesel. This unit is on a 39' Bounder w a frieghtliner chassis.
Any thoughts?

SarahW · 07-21-2014, 04:38 PM

From the Onan troubleshooting guide... (click to enlarge):

Kpjp · 07-21-2014, 06:58 PM

My last C+ Motorhome had a Onan diesel 7500. I had the same problem. The motorhome was in a side compartment and was difficult to access. The antifreeze coolant tank was located along the top and the oil dip stick went through the antifreeze tank. Onan glued a tube through the tank so the motor oil dip stick would run down the tube. Well as luck would have it, there was a slight leak around the tube which the antifreeze would run down the outside of the tube and onto the engine. As the tank was pretty cloudy, I could not tell if the tank was full without removing the side panel and using a strong flashlight to illuminate the antifreeze tank. After replacing the antifreeze tank and filling up the antifreeze, i never saw the error again. I guess the Onan generator needed the extra quantity of antifreeze to run properly.

Jim

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rjsupersonic · 07-21-2014, 07:29 PM

I had a similar problem with my Onan, shut off all loads to the generator and then start it. Usually after about a minute the inverter,fridge etc kick over to the generator mine bogged down at high altitudes, if you are over 5,oo0 ft adjust the altitude screw, after taking the loads off I let it warm up for at least 5 minutes then add loads. Onan says it has to do with the choke not opening up properly. I have not had them look at mine yet. PS mine is a gasoline 5500.

mrwrench · 07-21-2014, 08:22 PM

Quote:

Originally Posted by rjsupersonic

I had a similar problem with my Onan, shut off all loads to the generator and then start it. Usually after about a minute the inverter,fridge etc kick over to the generator mine bogged down at high altitudes, if you are over 5,oo0 ft adjust the altitude screw, after taking the loads off I let it warm up for at least 5 minutes then add loads. Onan says it has to do with the choke not opening up properly. I have not had them look at mine yet. PS mine is a gasoline 5500.

is that a primary or secondary code ?

Jonnyboy 316 · 07-21-2014, 09:00 PM

If the genny is cold but shuts down with a code 33 it may be a defective sensor. On my 7500 Onan, the sensor was impossible to get to without removing the generator from the MH. The temp sensor can short out and when it does it sends a hot code. If it is the sensor, it will send a 33 code even if the engine is cold. Good luck.