[MidnightAuto]

I am trying to trouble shot a self inflicted wound. In changing my in dash tach I seem to have shorted my blower control as it no longer comes on. I’ve got it all apart- there is a 4 prong switch that is for blower speed; as it stands there is no power going to any of those prongs. There are also two spades on the right side of the unit. One of those wires has power and the other does not. And lastly, there is a small 2 terminal plug on the far right as well. No power coming from that.

how does this thing work? I assume my problem was no power at selector switch- but I susoect there could be interplay with the other electrical parts I mentioned. Just need 101 on how power shoul flow through this part of harness…thoughts appreciated.

 

[MidnightAuto]

These are the two spades I was mentioning. I don’t know how power should flow to these. I also might have reversed these from original as the look the same. Right now only the right wire has power. Also note the plastic plug on right. No idea how current should work to that. Currently no power….

 

[PontiacJim]

View attachment 163391
View attachment 163392

These are the two spades I was mentioning. I don’t know how power should flow to these. I also might have reversed these from original as the look the same. Right now only the right wire has power. Also note the plastic plug on right. No idea how current should work to that. Currently no power….

Checked fuses?

Does not look factory with those 2 black wires. Have you tried to run a hot wire to the 4-prong switch to see if that energizes the blower? That would tell you if the switch is good.

Do you have a Service Manual and/or wiring diagram for your car? They should have something in them that will help if you need to trace wires.

 

[MidnightAuto]

Thanks pj. I did check fusebox. All seems well there. I did run a wire and Switch is bad, but I also don’t have power from esp any of the wires going into switch, so something not right there. ames is going to get back to me tomorrow. He was going to talk with tech. He thought those two black wires went to ac and powered the warmer to cooler slider. I have a wiring diagram but I am not an electrical wizard. There is a relay on the firewall under hood, that might be something to investigate