blower motor fan wiring

[MustangMark]

I am working on a 65 mustang and cannot get the blower motor working. I have 3 wires at the back of the fan switch that go to the resistor block. then there is a single wire at the resistor block that I don't know where it goes to, but it does not have power. i checked the fuse, and it is good.

 

[66HertzClone]

At this point you might want to use some jumper wires and wire the fan directly to the battery. This way you eliminate it from your troubleshooting tree. The single wire on my 66 is yellow, it connects to the bottom of the resistor plate, the three gang above the single wire below. Did you check to connections under the hood, you should find a brown wire and a yellow wire. The brown wire supplies 12v t other blower motor, the yellow is the ground and it connects to the resistor inside the car. I hope this helps, Jeff

 

[MustangMark]

before installing the blower motor I did check it for operation and it does work good. I cannot find a wiring diagram in the books I have. are u saying that the brown wire at the blower motor is hot, then the yellow is the ground and goes to the bottom of the resistor block. then has to go through the resistor, to the switch, and then the switch has to ground out? Are the wires from the bolwer motor still yellow and black at the 6 prong connector at the fire wall?

 

[66HertzClone]

At the firewall plug the wires should be yellow and brown. These are the colors of the two wires that connect at the blower motor itself. I can't believe they would change the color of the wire along its length somewhere.

As to the yellow wire, the current source is the brown wire, after the motor it becomes yellow, it then connects to the resistor. The switch is the end path to a ground, each detent selects a resistor thru which the current passes thru before reaching a ground. Does that help?

 

[MustangMark]

thanks alot, i have been able to draw myself a wiring daigram with your help.
I think i know enough to trouble shoot the problem.

 

[WORTH]

oops, there are 2 different wiring diagrams for the 65, one is as 66 stated the other is back asswards ,

yours may power the motor, or power the switch

unplug the blower resistor and see if you have 12 volts at your switch.

IF youu HAVE 12Volts at the switch, then all of the wires on the resistor should be hot if the switch is on, if they are not the resistor is BAD.

IF you do not have 12 volts at the switch then the blower is powered and it goes backwards to the resistor and then to the switch, and the switch grounds the circuit.

this is only in 65, from 66 up all have power to the switch first.

 

[MustangMark]

well, thanks all i got it fixed. powered the motor first. I don't understand why ford would have switched methods to powering up the switch first. controling the ground works a lot better, running less amps through the switch.