I'm having problems with my fan in my 98'silverado truck.When i turn on the fan for heat it won't come on and sometimes it will.The times it doesn't come on i may be going down the road and suddenly it comes on without warning(yes it is in the "on" position)when this happens.The only heat i get is coming off the engine until "it" decides to work and blow out heat.If i'm experiencing this now i want to have this resolved before the HOT DOG DAYS of summer.
THANX.
Maroon chev shortbed,rally wheels,dropped 2in. front,4in.rear,dual flows w/ 5in.chrome tips

Have you checked for loose wiring on the heater switch and fan motor? Maybe a bad switch? Have you tried jumping or bypassing the switch to test it?
If you access to your fan motor, you can verify it by running a wire from the positive battery to the terminal on the fan motor, it should run all the time a conection is made.

Thanx Wayner.

libb58,

My dad is having the same problem in his 2000 Silverado. I will post whatever I find... could you do the same?

Thanks

Bill

Don't know if the 98 are different than the 95's. But, the ac control board's on the 95's are junk. The ac starts doing all kinds of weird things. I replaced the board and all is fine. This has happened to me twice.

Hey stope4 where did you find the control board and what was the cost thanx?

Hey wildbillyt i will post all info when i get this resolved.

I found my GM dealer has an exchange program for the units with "United Radio." They repair anything, radio head units, digital dashes, AC head units, as well as OE radios for all makes.

This where I replaced my radio head unit for my 88 Truck, $85/exch.

Right before my 97 Silverado was stolen (I just replaced radiator plus newly rebuilt 4l60E)I had similar problems and think I located the problem but never had chance to put new one in. It was the flapper door switch by the gas pedal that went bad and as such wouldnt defrost window or heat well since only bottom opening was working. I took it off and could move it by hand and used a test light at the plug plus I noticed it smelled burnt.