70 Cuda non ac heater fan

[B5fourspeed]

My heater fan will not come.What is the best way to troubleshoot.Brand new dash harness and the heater box was re done.What fuse runs the blower.Thanks

[FE5CUDA]

The first thing you want to do is unplug the motor and put power to it to make sure it's not the motor.  From the bottom right of the fuse box it's the second fuse up from the bottom.  If the motor works and you have continuity on either end of the harness, it's just may be the switch.

[70rag383]

The first thing you want to do is unplug the motor and put power to it to make sure it's not the motor.  From the bottom right of the fuse box it's the second fuse up from the bottom.  If the motor works and you have continuity on either end of the harness, it's just may be the switch.

@FE5CUDA, I'm having similar issues, only when I turn the fan switch on it fries the fuse. How do i put power to the fan motor?

[B5fourspeed]

I ran a wire from the battery to the fan wire to test the fan.The fan works.Then I notice on the wiring diagram there is a connection for the power wire for the fan switch about a foot up the harness.2 black/white wires above steering column that were not connected.I was able to connect them and now the fan switch works.The wires were right in the middle of the steering column support bracket.

[70rag383]

@B5fourspeed where is the fan wire that you connected the battery power wire to? I need to run the same test.

[B5fourspeed]

 It is the single wire that is on the top of the heater box.It is connected to the resistor.You can get your hand in the space on top to disconnect it.

[anlauto]

You would have to unplug the green wire from the top of the heater box and put power to it, to test the fan motor. Or to test the resistor, leave that green wire plugged in, and unplug the dash harness from the resistor and put power to either spade on the other end of the resistor...

[70rag383]

Thanks guys, I may have to remove the glovebox liner to get to it.