It seems like my cooling fan is not engaging when it's suppose to. When I turn the ignition off I don't hear the chirp anymore. The only thing I did out of the ordinary about 24 hours ago was playing in the mud but I don't think that will affect the cooling fan. Other than a blown fuse, what would cause it not to engage? I would like to hear from you guys before I take the truck to the dealer.

Thanks.

 

First off you are in IL, I don't think it would be HOT enough there for the fan to even engage. The Chirp that yo may have been hearing was the A/C because you had on the A/C or the Defrost which turns on the A/C.
If you really want to check the fan out then cut your self a piece of cardboard and block out the radiator. Drive the truck around until the temp starts to get up above 200 and see if the fan kicks in then If it doesn't kick in by 230 then pull over and remove the cardboard. This will also set the code for the dealer to have something to look at

 

Other than a blown fuse, what would cause it not to engage?

Are you saying the fan is electronically controlled?

 

The chirp is from the belt slipping. The engine sometimes stops faster (because of high compression) than the accessories can. They want to keep turning, so their pulleys slip the belt a bit. That's the chirp. In cold weather, the trucks often don't chirp. Mine chirped absolutely every time I turned it off, regardless of climate control settings. Then, the first time the temp dropped below about 60, it didn't chirp. Once the engine warmed up, it started chirping again. As far as I know, the fan is not related to the chirp. If your engine is not overheating, you have no problem. Just assume the lack of chirp is due to cooler weather, and carry on.

 

Thanks for the reply guys. The chirp we hear is the cooling fan disengaging when the ignition is turned off. You can verify this fact if you read the black tag that was hanging on the cigarette lighter when you first bought your truck. If you still have this tag read it. You can find this info at the bottom of the tag.

The reason why I'm concern about the absence of the chirp is because regardless of the outside temp (summer or winter), I always hear the chirp when the engine has reached operating temperature.

 

My 99 an 03 both chirped at different times usually when it is hot out. I did have one experience on my 03 concerning the fan. When I first bought it there was a Recall to check the tightness of the fan on the water pump. They checked it. about 5000 miles later on a hot day I was parking at home and heard a slight clunk not a chirp when I shut it off. I didn't think to much about it. Went back out to go somewhere and as my speed increased I kept hearing a grinding clunking sound. I shut it off and looked under the hood and was amazed to see the Fan had unscrewed from the water pump the last time I shut it off (the slight clunk) and was sitting in the fan shroud. The noise I heard while I was driving was the fan blowing back against the water pump shaft. Believe it or not the only damage was to the fan where it buggered the threads up rubbing against the water pump shaft. What we did find out was the clutch on the fan had gone south and was not releasing the fan so when the engine came to a high compression instant stop the fan had no slippage and just unscrewed itself. I did learn The only time you really nead a fan is on a hot day stuck in traffic towing a huge load. I drove it a couple days without a fan and it never acted any different. It didn't chirp and had no fan howl! I kinda have a feel now how tight the fan should feel when the clutch is realeased If it gets tight when its not running somthing is up. Oh yea it is electronically controlled with a harness connected to the front of it. I would be more worried If it was working all the time (fan howl) than not.

 

You should not hear any belt chirping at all when the engine is running. The only known chirp is the shut down chirp on automatic trans trucks.

The belt should not chirp when the AC clutch engages (like my 99 does w/ Horton fan).

If you want to test your fan, turn on the AC max cold, with the engine hot, bring the rpms to around 1500, . The fan comes on to cool off the AC compressor. If the engine is cold , it takes a long time to engage the fan because the fluid in the fan clutch is very viscous (thick). As the heat builds up, the fan clutch fluid becomes less viscous (thinner) and the fan can engage quicker.