I've read alot on what goes wrong, blower motor stops working, heater core gets clogged, and even the switch on the dash itself craps out after a while. When I try to turn on my fan, basically nothing happens. There is a little noise when you initially flick the switch, but nothing happens. If I recall when you are traveling highway speeds a little heat creeps out if you turn it on, but there isnt any forced air being pushed through.

My first guess would be to test the blower motor, but I have no idea how to do this or what to look for. I do have a meter but I just have no clue how to test it. Thank you guys very much.

91 s10 blazer 4x4

 

first of all, thanks for including your truck info. helps alot.

first thing you'll want to do, is to check the grounds on the firewall near the blower motor. if i remember correctly (it's been awhile since i messed with a year-round 1st gen) there are 2 grounds there for sure. i think there is 3 if it's an A/C truck.

if there seems to be an issue with them, just drill another hole & run in a self tapping screw. clean off the paint before installing the wires again.


after that check for corrosion @ the speed controller located on the engine side of the air box.

also verify the voltage to the blower motor plug itself. i've come across 1 truck that had some internal corrosion going on in the power wire. caused enough of a drop that it wouldn't work when the it was cold out. but if the truck got hot enough under the hood, it would work sometimes.

keep us updated with your progress or findings.

 

Thank you very much. I unclipped the power to the blower motor, first things first. Checked for power..none. Dead. Went to my fuse box and pulled out that blown 30A and replaced it. Works like a dream now, all setting and speeds work along with my defroster and rear. I've never had the heat working in this truck, and the previous owner owns a shop and said he couldn't find out what was wrong with it. Had no idea it was going to be this easy. Thank you guys.