Blower Motor Not Moving Much Air

[Tractor Dan]

Here is what's going on. I drive into town the other night and notice the blower motor isn't moving much air as in i can hardly feel it coming out of the dash. I tried all positions of the switch and got nothing out of low, the motor runs on medium and medium high but not that fast, and then on high it runs but not much faster than the previous two settings. So far i have checked the resistor pack in the heater box. Checked resistance and all resistors had resistance. So i put it back together. Was gonna drive it tonight and turn the blower on and i'm getting almost no air out of the vents but i can hear the motor spinning just really slow.

So my question is what should i look at next the switch or the motor? I know the motor is easy once i get the airbox out of the way simply apply 12V and give the motor a ground and if it spins up the motor is good. If not replace it. I'm half tempted to replace the resistor pack simply because it's relatively inexpensive and seems to be a common failure. I'm guessing mine is as old as the truck or atleast fairly old because when i unhooked the wire cluster plugged into it a bunch of dust from corrosion fell out from the connector and part.

Also if i test the switch how do i get out of the dashboard? I haven't had a 94 dash apart. My 97 was easy simply removing the bezel and then had i wanted to pull the HVAC controls a few screws was all it took.

Any help is appreciated trying to get this straightened out before i head back to school next week. I finally got heat in it after replacing a bad thermostat.

 

[deankelly]

Before replacing any parts run good power direct to the motor to verify it works at full speed. If it does, back track the circuit to the resistor block. Check each leg for the proper resistance. After this many years it is very possible that the solder connections have weakened. If it tests ok for resistance test for voltage at each setting to the correct pin. I suspect that if the motor tests good the resistor block is the most likely part to fail. You did state that the fan operated in all switch positions.

 

[Derf_the_Mule]

I am not sure about the '94, but my '07 had the same problem. I replaced the resistor (should've tested it first) it was corroded. Went to replace the fan and found the screen ahead of the blower was nearly completely matted with dog hair and trash from PO. I accessed the inside of the screen from behind the glove box and was able to get a crevice tool to the screen via the recirculating air intake. You can shine a light in there from the glove box to see the inside.

I recommend looking at the screen (if you have one) first then testing the resistor. There is a really good article on testing that exact resistor somewhere on the internet. I tried www.aa1car.com, but it may have been another website. I'll post it if I can find it.

 

[Tractor Dan]

Thanks for the info. I think i'm going to pull the switch first and test that to make sure it's functioning correctly. Then i guess i'll try jumping the terminals on the harness that would make the fan run at high speed. If that works i would figure my motor is ok and if the switch is ok it's the resistor. Figured this is the easier method to test the motor without taking the airbox out of the engine and whatnot. I honestly don't think it's the motor because it's spinning free and no sounds like it's binding or anything. My guess is the resistor but i want to cover all bases before i replace anything.

 

[Andy D]

If the motor works on all speeds the resistor pack and probably the motor are OK, I would suspect clogs or a hosed up blend door.

 

[saskbill]

My hands-on experience is with pre-94 rangers, but this video indicates the fan motor is still accessible form the engine compartment:

https://www.youtube.com/watch?v=BEqUdS5C6ns

I'd suggest - pull the fan and motor out and see what else is in there - I've seen one near packed full of leaves!

 

[Tractor Dan]

If i can find a garage to get in out of the wind i might try pulling it. I think while i'm working on all this regardless i'm going to replace the resistor pack. It's only $28 and gives me added insurance that i won't fix one thing and have it go bad on me later. I'm trying to not put too much into it till i decide if i'm keeping it or selling it.