Weird wiring problem

Midwest_Mudder

New Member
Typically I'm pretty good at figuring out wiring. But this has me launching random sockets across my garage. my Windows, seat, and heater control don't work. I can jumper the power main relay and get my Windows and seat to work. That led me to believe the relay was bad. Tested out fine, checked the other two pins, and discovered both sides had a 12v. Which is also the issue at the heater panel, the ground location is showing 12v. Makes sense because they both eventually tie into the ground that terminates at the drivers kick panel set bolt. There is no power making it to the ground. So by the tsrm I need to find j/b number 7.

Unless I'm missing something obvious.

what i know:

the power main relay should have 12v on pin 1 (lower) and ground on pin 3, however i have 12v to both plugs
if i jumper 2 and 4 i get my power windows and side/lumbar control
2 climate control units DO NOT work, both tested fine in another car.

all my Circuit Breakers are good, none are setting off, all fuses replaced with brand new fuses of the proper size.


the odd thing is, it was all fine one evening, then the next morning nothing worked.
 
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hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
12,568
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Fullerton,CA
For your heat. make sure the the heater valve on the firewall is moving. You can apply vacuum straight to the valve with the engine running and the little arm should move up. If it doesnt its siezed and you can try moving by hand.

How did you check the relay? Did you apply power and ground and then check for continuity on the switch side?
 

Midwest_Mudder

New Member
heaver valve is good, moves freely, all the doors work, the motor is free and works, blower motor resistors are all good. heater cb is good, heater relay is good, power cb is good, power main relay is good. the ground at j/b no 1 set bolt has no 12v, but the ground at the power main relay shows 12v as does the power side. i need to double check the ground that connects into the heater control box (w/b wire pin 10) but i believe that was also showing 12v. thats where i got the J/B no 7 idea since thats where those 2 grounds come together before going down to the set bolt
 

Midwest_Mudder

New Member
positive. gauges all work, dome fuse is good as well

little update. the grounds do NOT go to ground, SO, my relay is backfeeding rather than going to ground. i have to have a cut line somewhere. 0ohms between the grounds (heater and power main) but OL between either ground and the ground.
 
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