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Robert, RV Mechanic
Category: RV
Satisfied Customers: 13511
Experience:  18 yrs. RV experience including Cummins North West, Country Coach, Monaco Coach - vendor certified.
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I have a 2008 Fleetwood Revolution 42N 400 cummins that is

Customer Question

I have a 2008 Fleetwood Revolution 42N 400 cummins that is running hot, on flat land, its running between 199 and 205 with or without the AC on. The outside temp today was 103 degrees.
I have had a tech out 3 different times, he found a blown fuse to the hydraulic cooling fan and that the fan is not always going into high mode. He has serviced the radiator, cap, coolant and is sure it's not the thermostat.
How is the hydraulic fan powered?
What controls the speeds of the fan?
Are there any common issues regarding the cooling fan?
Are there any common issues regarding 400 cummins running hot?
Thank you
Submitted: 1 year ago.
Category: RV
Expert:  Robert replied 1 year ago.

Hi my name is Robert....

Few things, first make sure the radiator is very clean, if it was plugged with debris it would not help matters at all, normally a good steam cleaning will get them clean.

The thermostat could be the issue but that fan should be kicking into high speed, most hydrualic fans use a fan controller that will be mounted to the radiator shroud or near by... So it is possible the fan controller is at fault, I also want to say that a cummins shop with the insite software can hook up and check the settings for the fan. IF you were to unplug the fan controller the fan should kick on high speed. The other issue is the actual fan. I think on this one I would try to have a Cummins shop take a look, I used to work at a Cummins Coach Care and they have the ability to troubleshoot this.

I am not aware of any issues with the ISL 400 engine, it is a good engine, it sounds to me the fan not coming on high speed is the issue...

Hope this helps some, IF you have more quesitons or concerns please feel free to contact me... Robert

Expert:  Robert replied 1 year ago.

Hi... I see you have not selected a rating, if you still need more help on this please let me know...