1998 Ford F-150

One day last week, on my way to work I had no heat, I could hear the damper moving from pos. To pos. But no blower. Left work to go get lunch and it worked, all speeds.
Tonight it happened to me on the way home, no heat blower. If I put it up on the panel, I got VERY LITTLE heat coming out of the vents.

I also have an intermittent wiper issue. It seems that when the truck gets wet, the wipers won't work, you can hear the motor trying to do something. But nothing's happening. Then, 5 miles down the road, bingo they work!

Short of having a possessed truck, I can't afford these problems! I'm on a volunteer fire dept/rescue squad that runs over 1000 calls a year! Whether it be from having no defrost to help me see a little clearer or no wipers, I can't go ANYWHERE! HELP!
January 10, 2006.

Sounds like the blower motor has a bad spot. Also sounds like you need the Wiper Control Module, its a common problem with GMs

Jan 11, 2006.
Blower motor for sure it's located under the dash on the passangers side. And replace the wiper module or it could be the motor or connection

Jan 16, 2006.
It probably is the wiper motor, I had to change mine. It's been a recall issue with GM's for a number of years. If you're really handy you can take it apart and weld the solenoid housing. That's what cracks on them.
Nothing is built well anymore!

Jan 16, 2006.