Hi All, thanks for having this forum. I'm trying to diagnose a problem with my A/C system. There is no air motion at all. I checked the resistor and it looks ok. No corrosion. But now I would like to check the blower motor and I can't find it. I'v seen some YouTube videos but they all have a different blower motor location. Right there under the glove box where you can see it and easily remove it with 3 screws. I hope I don't have to remove the whole dash board.

 

It IS under the glove box.

Lay on your back, look up under the glove box.

That big black box hanging off the dash? Is the HVAC box.

The two big wires running down and towards the passenger side fender (not into the fender, just running thataways)? That's the power for it.

The 1995 and 1996 FSMs are here for download in the FAQ; THAT part is pretty much the same (a few part numbers changed, but the mechanics are the same). Download that and look at it.

Be sure to check Fuse 4 (the 30A unit). If it's an ATO, make sure that it has 12V both sides with the ignition switch ON (in case it's blown, or if it doesn't have 12V on at least one side, you may have a bad ignition switch.)

Also, when you find it ... disconnect the blower motor from the truck's wiring. With the ignition ON, make sure one of your terminals (should be the brown one on the connector to the truck) has 12V on it. Again, if you don't have 12V there, it's a wiring problem to the blower motor. The resistor and switch are on the GROUND side, so that also should have very low resistance to negative with the fan speed set to HIGH.

With it disconnected, also check resistance across the blower motor, make sure it's not open.

EDIT: Forgot to mention - good news, you won't have to pull the whole dash to get it out. I THINK you can reach it with the box installed. Even if you have to pull the dash, only the lower half dash comes out. And that'd be a perfect time to add a LED strip (bolted into place!) to the bottom, with a 194 type connector, to add a courtesy light.

RwP

 

Thanks RalphP, I'll look again. Thanks also for the diagnostic tips. Sounds like they are based on hands on experience. With the resistor in place and plugged in I can hear the motor trying to run but not blowing. I'll let you know what I find. Regards, Jim

 

After meeting with much frustration, and not finding the blower fan, I decided to try something else. I replaced the resister with a new one and the fan came right up to full speed. The heater works great but the A/C wasn't chilled, but I learned that my Freon was R12. and not charged. I am now in the process of upgrading to R134A. I should have that done soon so I'll follow up with the news. I'm sure it will be good.

 

Dude.

It's not hard to find.

It may be internal; I found out that the 1991 has the fan INSIDE the HVAC case.

You do need the factory service manual if you're working on your own truck.

RwP

 

I have upgraded the refrigerant tt had been R12 and is now R134A. I put in a 20 oz. can and it seems to be enough, but I can't tell because it is a chilly day here. It's holding the charge just fine.If it's not cool enough on a warm day, I'll give it another hit of freon. But everything seems good for now. Thanks for all of your help (and patience) It has been a learning experience. It was also a good excuse to acquire some new tools. A manifold gauge set and a vacuum pump. All's well that ends well. Good time to close the thread.