1978 Trans AM power windows tach and heater blower issue

F

ff14778

New member
Joined
Sep 11, 2019
Messages
3
Reaction score
0
Points
1
I just replaced my valve cover gaskets. I had to remove the AC brackets and other little stuff to make room. After I reinstalled them the tach blower and power windows do not work. I checked the wiring around the area I was working. I did have to disconnect a ground wire connected to one of the AC mounting brackets. I checked the ground by attaching another ground wire directly to the negative on the battery. Still nothing is working. Does anyone know what may have caused all three to not function? I looked at the heater fuse looked good but did not test it.
please help. thanks
 
well your tach is powered by a wire coming out of the distributor cap, have you looked to see if that wire is still plugged in? The cap is marked TACH. Did you look at the power window fuse and it might have a relay, refer to your owners manual electrical section. The HCAC blower also typically uses a high speed relay and a resistor for the lower speeds. The resistor is usually mounted on the AC?heater box in the engine compartment.
 
Yes, I checked all of those connections. It is just strange that all 3 went out at once. The only wire I disconnected was a ground wire with three leads connected to the AC bracket on the motor. I thought it was that, but I rerouted that to a good ground. i cannot find anything in the wiring diagram that feeds all three of these items. I will check the heater fuse today. looks like the Tach power feed may run off that on the fuse box. I found this so maybe it is the power window circuit breaker.
The power wire plugged into the spare ignition terminal on the fuse box (see the power windows page). The power window relay and cruise control were also powered off this one terminal, so jumpers like the one at left were required to power two or more of these options.
I have seen many variations in these harnesses. Some omitted the fuse, some had built-in jumpers (as shown below on the power supply to the pulse wipers), and there was a combined cruise control and tach wiring harness with only one power supply.
 
I found out looks like the power feed for these three. Does anyone know what wire feeds this circuit?
______________________________
 
Would like to ask person ff14778 if he found a resolution to this problem. I have the same issue with no
power to tach or blower motor (but I don't have power windows). Thanks
 
You must log in or register to reply here.

Share this page

Back
Top