Heater not getting power

[jdickson]

Hi everyone I have an issue with my heater and have not been able to figure it out. My blower wasn’t getting power so I swapped the relay, resistor, and switch. I also ran power straight to the blower and it works.

I tested voltage and am not getting power to the purple wire at the relay or any wires in the switch.

I tore all the lumes off and traced the wire from the fuse box and found that the wire is cut however I cannot find another wire for it to connect to. The wires from the relay/resistor to the switch are all in tact. I looked at the wiring diagram that shows it should be tying into a yellow wire but there is also no yellow wire at the resistor or under the dash I could tie it to.

Any ideas on where this wire is supposed to tie into? I have a 82 C20 with an AC option.

 

[Jgonick]

I tore all the lumes off and traced the wire from the fuse box and found that the wire is cut

What color wire is cut? I'm confused about which wire you found cut.

I looked at the wiring diagram that shows it should be tying into a yellow wire but there is also no yellow wire at the resistor or under the dash

What is "IT"? the cut wire?

see attachment- your setup looks like this- correct?

 

[jdickson]

The cut wire is a brown wire that goes straight from the fuse box in the cab under the E brake pedal to behind my cluster and then is cut.

I’ve followed the wires from the relay/resistor to the switch and there’s no cuts or breaks.

 

[Jgonick]

To confirm- your truck has AC? are you using the diagram that I attached in my previous post or are you using one that looks different? I'm still trying to figure your setup


Does you truck have gauges? (I'll explain later)

 

[jdickson]

To confirm- your truck has AC? are you using the diagram that I attached in my previous post or are you using one that looks different? I'm still trying to figure your setup


Does you truck have gauges? (I'll explain later)

It does have the AC option but the guy I bought it from cut the ac lines and there’s no condenser.

The diagram I was using looked different from the one you sent me. i found out that if I splice that brown wire from under the dash to the brown and black wire in the switch everything works accept the high speed. It’ll blow the fuse instantly if I do that.

 

[Jgonick]

Use my diagram and see if it makes more sense. BRN-50 coming from fuse box should go to selector switch. (It might also split off and go to generator/alternator light in instrument cluster if you don't have gauges) The selector switch is where you turn it on and choose A/C, heater, vent etc.. a BRN/WHT wire should go from selector switch to Blower speed switch.

 

[jdickson]

Thanks! It worked I was able to get it to turn on and switch through the speeds. It blows my 25 amp fuse every time I turn it on high but at least I have heat now