Rickcher

Does your HVAC fan control switch work off of a vacuum line? Mine is working intermittently and I have no power at the blower motor. Just trying to get an idea before I take the dash apart. Thanks.

wannadiesel

No, the vacuum runs the pods that move the mode doors.

Rickcher

The fan stays on low no matter what position I put it in (I can feel a little bit of air coming out of the vents). I can also feel a little bit of air coming out of the defrost vents if I switch it to defost, etc. But I don't have any power at the blower motor. Where should I look next before I pull the dash? The fuse is good.

comptz

Have you looked at the resistor behind the glove box? It is located above the black box for the rawl. Mine was loose and that fixed it.

Rickcher

I haven't checked that. Is there a wiring harness plugged into it?

comptz

yes, i can take a picture of it if you want me to.

NO_SPRK

Take a pic please. My blower motor works if I hot wire it but other then that nothing else works electronically. The vacuum part works. I took my dash apart one day and I got the blower motor to turn on for a second. Also my a/c motor isn't locking up

comptz

the plug that is circled in yellow is the resistor plug.

Rickcher

Thanks! I'll check it tomorrow. If I have no voltage at the resistor, it has to be somewhere between the ignition switch to the fan switch to the resistor, right?

comptz

I believe so. Did you get my pm?

justin mcfall

Check the wires going into the blower motor under the hood. Mine will do the same thing at times,and i just pop the hood and wiggle the wires to the blower motor...

NO_SPRK

I checked my fuse box. That resistor thing. I put a new fan switch in and still can't get my fan to turn on or my a/c comp to lock up

comptz

You might try checking one of the fusible links on the fender

Jim Lane

Pull down your fuse panel and look behind the fuse and see if the wire is burned, mine got so hot that it melted the fuse and burned he panel. All of the current is drawn from the ignition switch.

Check my article on the blower motor; I have the wiring diagram of the blower circuit.
https://www.dieseltruckresource.com/...d.php?t=158400

Jim

Rickcher

Comptz, Got your PM, thanks. I have no power at the fusebox but the fuse is good (or at least it's not blown). Blower motor works running straight off the battery, so it's good.