HVAC Blower Motor Not Blowing Like It Should

[Foxracin]

First off its a 1991 Explorer. When the blower the fan is on high it barely puts out any air from the vents. Almost feels like what low should.

Here is some background info. When I first got the Explorer the blower motor resistors were burnt up and there was a hole in the box. I patched the hole and sealed it all off under the hood. Only high will work because it by passes the resistors and goes straight to ground.

Before I patched the hole under the hood when it was on high it would blow air out of that hole like no tomorrow like it should. Patched the hole and it made no difference in the air coming out of the vents.

Its like a door isnt opening or something is clogged. I am find with it just working on high for now until i get the stuff to fix it.

So what are some thing I can check look at to make sure nothing is clogged or anything?

 

[fixxxer]

On the board that has the blower-motor resistors, there is a thermal cutoff fuse shaped like this --|===>---
If you put a jumper across this and remove your other bypass you will get all fan speeds back again or you can spend the $20 for a new blower-motor resistor assembly. As far as the door for diverting air to the floor or defrost or the vents, those are vacuum actuated (vacuum motor) and are under the dash, next to the heater core housing on the right side of the plenum. You can access it from behind the glove-box, you have to remove the glove-box to get to it. Also, check the air inlet. That is where the blower motor pulls in fresh air from the outside. The inlet is at the bottom of the windshield, passenger side, just above where the blower motor is.

 

[Savage22]

mine was doing the same but turned out to be a mouse had built a home inside the blower fan area. it was completely PACKED. cleaned it out and runs fine, a bit noisy but puts out air. just a thought.

 

[Foxracin]

Keep the ideas coming. Ill probably take a look at it this weekend.