fresh air blower, where's the hot lead? Options

[jr91472]

Didn't want to hijack and my issue is a little different so........

Can someone explain to me where the hot lead is located on the fresh air blower switch in the dash. All I can find is one red wire that goes into a small lamp socket next to the dash board lever.

I have three white wires (w/ stripes) that control the fan speed. Then one ground wire on top of the switch unit and another ground wire on the bottom.

This seems consistant with the wiring diagram, but I cannot figure out how this circuit works. The only place I can find 12v is if I pull the lamp socket out and probe at the end of the red wire. Once I put the lamp socket back in place, nothing. Is there some kind of contact inside the lamp socket?????

btw, the little light bulb is burned out, don't know if that matters or not.

thanks

[Joe Ricard]

Hot lead is the red wire that goes into the plug at the blower. Real tough to get to unless you got girlie man hands. Passenger side of housing at the rear of housing.

Like I said before the blower always has power with ignition switch on. All you are doing with the blower control lever is selecting which wire is grounded in relation to the resisitors inside the blower housing.

[jr91472]

yeah i figured it out. Turns out the little light bulb was not seated properly preventing the connection to the brown wire jumper that goes back to the bottom of the lever.

Everything checks out now except, no blower. Think it is dead.

[Joe Ricard]

Maybe I am confused with the other thread. Just reach up in behind the blower housing on passenger side. pull the square plug out. Red wire is the 12V to run the blower fan.

The light bulb which indicates the fan is on has nothing to do with making the fan run.

The other thread said the fan ran in low and medium speed so obviously that fan motor is good.

My fan was stuck. I pulled off the hose coming out of the drivers side fan housing and used a stick to try and turn the fan. Stuck stuck.

Pulled gas tank and eventually fan housing tore it apart and used PB blaster to free up the bearings. then electrical contact cleaner to get all the oil and grunge out of the motor. Runs all three speeds.

[jr91472]

me too, I have been chasing multiple electical problems all day. I think I am getting MY wires crossed. (IMG:style_emoticons/default/wacko.gif)

I understand the square plug that connects to the blower. What I am trying to do now is connect 12v directly to the blower (bypassing the dash board switch) to see if the motor will run.

What I need to know is which of the four terminals on the blower is 12v. Then I can connect power to it directly to see if it works.

thanks

[jim_hoyland]

Im still working on getting my high speed setting to work; I have a spare control unit on my desk. A couple of the wire's were cut:
The fan bulb has a red/white stripe and brn/white strip wire. Believe the brn/w connects to underside of slider's brn--right ?
Where does the red/w connect ?

If you remove the whole unit, should the wire cable be disconnected at the dash end or the vent end ?
I would like to replace my old unit.

[Joe Ricard]

Well it's one of the 4 wires on the plug. You can be brave and lift the cover off the plug and see which ones the red wire is hooked to. Just be careful not to let the wires come out of the connector or you will goe nuts figuring out which one goes where again.

Did you see if the motor / squirrel cage fan spins freely? If it doesn't don't bother hooking power to it. just pull the unit and fix it.

You can jumper a 12v wire and a ground negative wire straight off a car battery. Worse that can happen is you run the motor backwards. suck instead of blow at one of 3 speeds.

[Joe Ricard]

Forgot to mention AGAIN the damn light bulb red wire DOES NOT have ANYTHING to do with making the motor run!!!! (IMG:style_emoticons/default/wacko.gif)

[jr91472]

Thanks Joe, I tried every combination of connections by running a couple of leads straight to the battery. Looks like I will have to pull the blower.

what sucks is that I had the tank out less than a month ago (IMG:style_emoticons/default/ar15.gif)

don't know what I was thinking about the bulb (IMG:style_emoticons/default/chairfall.gif)

later

[Joe Ricard]

Ya, and now you have to resist the urge to clean and paint everything up under the blower. And then the "while I'm in there" stuff like clean up the windshield wiper motor and linkage. get at them little corner pockets aft of the wheel well arch.
Replace the foam seals in the ducting flapper valves of the blower housing. I used the bottom of a beer can snuggy. just trim the foam to fit.