The blower motor stopped working in my 1990 F250. I can feel the switch catching when moving the switch from position 2 to position 3...and, the 3 lowest settings never really did work, only the highest setting. Now the blower motor won't even come on at all??? Anyone know where to start looking to diagnosing the problem? Also, is there an under-hood fuse box that holds the fuse that powers the blower motor?

Thanks for the help guys,
Hunter

ps-I also posted this in the pre-1997 area.

 

As far as the low settings never really working, that can normally be blamed on the resistor block crapping out. Not working on high? Check for power at the motor. If you have power, replace the motor, if not, trace the wiring back until you do.
Isn't the fuse for the blower motor under the dash?

SL

 

Yeah, I found the fuse under the dash. It looked OK, but I replaced it anyway with no change. Can I check for power with a light bulb style tester, or will I need a multi-meter? I also pulled the blower motor...everything looked nice and clean inside.

Thanks,
Hunter

 

Provided the bulb is 12V, yes, but a good multimeter is a valuable tool in any tool box.
Does the motor spin freely? If so, apply 12V to it and see if it kicks on. Be warned, if you plan on doing this while holding it in your hand, be ready for the torque kick. If you have one, use a vise.

SL

 

Good news...I tested the motor and it still works. I called autozone and they didn't have the resistor pack, but they did have the blower switch. So I said what the hell, I'll try it. When I removed the old switch I noticed the plastic piece that the switch plugs into was partly melted. I plugged in the new switch anyway, and ding, ding, ding...It works. It still only works on high, so I guess I still need the resistor pack. Does anyone know where I can get the resistor pack, no one around here seems to have them? How about the burnt peice that the switch plugs into? Thanks everyone for helping me get my heater going again. The morning drive to work the last few days has been awfully chilly.:santa:

Thanks again,
Hunter

 

Some auto parts stores stock or can special order the resistor block made by Everco/Murray/Four Seasons. If not, the dealer should have one.
Normally the connector is a junkyard item, but Motormite/help may offer one. Even if one is not available, the plastic piece is not important as long as the spade connector fits snugly on the lug of the switch.

SL

 

Thanks SL. I just want to make sure that the connector doesn't start a fire or something.

 

i just replaced mine. it's located above the feet of the passenger. i took it out and went to autozone. they had a book and we just went through the pictures. it turns out to be a Mazda part, the picture matched, and I know Maza makes other Ford components so I ordered one. Item came in three days later and matched exactly. fan works in all positions now.