Hmmwv overheating 220-240

[Rob T.]

If the fan is on all the time your fuel consumption will go up and you will loose some horsepower
Check the time delay, if the insulation on the wires is failing, you should replace it.
Make certain when you replace the thermostat that you get all of the air out.
Also check the coolant surge tank, remove the small coolant lines to check if the nipple is blocked, that is also a common problem
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Thank you very much. Also had an overheating problem with my 6.5 engine. One of the nipples was blocked with a little cord of silicone. Hope the problem is gone now. Still have to test it.

 

[troyperez]

Bigfan, the time delay module is the small rectangular box with the wires coming out of it and the Kysor Cadillac solenoid valve is the thing with the gold end. When the valve is disengaged by either unplugging the solenoid or the TDM it causes the fan clutch to engage. This is the fail safe mode of operation and other than being loud while driving and sucking up about 10 of the 150 HP your engine is putting out it won't hurt you to drive that way. When I first got my truck I had all kinds of problems with this and installed a switch to either let the fan run in auot mode, always on, or always off. That's the switch in the picture below. I would use a thread sealant rather than teflon tape on the fittings because you don't want to get tape anywhere in the hydraulic lines.

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Which switch did you use and how did you wire it up? Do you have pics?