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  • 1965 - 1973 Classic Mustangs -General/Talk-
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Heater Wiring (Painless)

  • Thread starter Thread starter golf4283
  • Start date Start date Nov 9, 2009

golf4283

Active Member
May 30, 2003
1,253
1
39
Orland Park, Illinois
Nov 9, 2009
#1
  • Nov 9, 2009
  • #1
Ok so I'm down to two last gremlins on my installation of the 20120 harness into my 1966 Coupe. My questions regarding the heater wiring. I know and understand how it works but my problem is I'm not getting power to either of the yellow or brown wires that are under the hood that are supposed to connect to the blower motor.

I checked the fuse and it hasn't blown so It's not that. I can't figure out any other reason why I don't have power going out there. Anyone have any problems with this or maybe know of a solution. I was also thinking that all I really need for the brown wire I can replace with a 12v ignition source and that would make it work but at the same time it should be working as it should with the brown wire giving the 12v.

Thanks for any light that can be shed on this problem.
 
S

sparx

Member
Sep 2, 2009
369
1
19
Nov 9, 2009
#2
  • Nov 9, 2009
  • #2
I have my heater box and motor out of the car so I am familiar with the circuit to a certain extent.

You might want to check the blower motor resistor that is attached to the face of the heater box, below glove box under dash. There is a connector that plugs into the resistor right on the face of the heater box, that connects to the heater switch. The resistor coils are on the other side and sample air temp inside the heater box.

The yellow off the motor runs through the resistor and the brown runs to the fuse block for 12 volts+.

So the yellow is a switch controlled negative through the heater switch then the blower motor resistor.

Also if you have 12 volts with a test meter at the blower motor, the motor is shot.

HTH
sparx
 

golf4283

Active Member
May 30, 2003
1,253
1
39
Orland Park, Illinois
Nov 9, 2009
#3
  • Nov 9, 2009
  • #3
yea I know how it works. I'm saying my brown wire in the engine bay doesn't have any power flowing through it to the blower motor and it should.

It's not the fuse either so I have no idea. I posted this on Painless' website as well as maybe they know of something I'm missing. I'm so close to having all the kinks worked out and this is the biggest one yet.
 

Tim65GT

Active Member
Feb 24, 2004
1,149
2
39
West Texas
Nov 9, 2009
#4
  • Nov 9, 2009
  • #4
I am assuming you are wiring it up for the 3 speed blower. Do you have the Blk/Wht wire connected to the Brn (904) wire?

 

golf4283

Active Member
May 30, 2003
1,253
1
39
Orland Park, Illinois
Nov 9, 2009
#5
  • Nov 9, 2009
  • #5
That must be it! Thanks Tim. In my diagram it didn't show you had to connect those two. I'll have to try it next time I'm home. Too bad that's not for another 2 weeks as I'm out of town for work.

Thanks again! If this works my last issue will be the blasted windshield washer motor which I think I can figure out.
 

golf4283

Active Member
May 30, 2003
1,253
1
39
Orland Park, Illinois
Nov 9, 2009
#6
  • Nov 9, 2009
  • #6
Looking further it seems the painless diagrams were updated at somepoint. The manual that came with my kit is an old black and white version. The new color version on the website is very nice. It's too bad I already figured out most of my problems except for this one heh.
 
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