Having problems with my belt squeaking.
1) It normally happens when I start my car cold or after driving for a while.
2) When I turn on my A/C, Heat or Defrost.
3) When I accelerate from a stop light with the Heat or Defrost on.

So far I have tried to put a little WD40 on the fan belt which did not help.
I have turned the ignition to on and turned the blower on and off with no squeak
I didn't see any water on belt from possible water leak.
Also belt does not seem to be loose or cracked.
Pulleys don't look to be loose and tensioner seems to be okay.


I have a 1998 Ford Explorer 4WD with 260,000 miles on it.

 

That sounds like a belt that is slipping, either because the belt is worn out, a pulley is causing excessive drag on the belt, or there is a build up of dirt and debris in the grooves of one or more of the pulleys.

Now that you've sprayed WD40 on the belt you may as well plan to replace the belt anyway. While the old belt is off, spin the idler pulley, tensioner pulley, and alternator pulley to make sure they all spin freely and smoothly. If there's even a hint of a chirp or squeak spinning it by hand, that's probably the issue.

Also with the belt off, inspect all of the grooved pulleys for a build up in the grooves. If you find a build up, clean it with a steel brush, flat blade screwdriver, pick, or similar. Clean all the pulleys afterwards with brake cleaner, let the cleaner completely evaporate before installing the new belt.

-Rod

 

Thanks for the help. I will post my results in a few days.