Heating wiring question
 

Hey guys, brand new to the forum. I've read many threads but can't seem to find what I'm looking for. Hoping someone can help me out.

I have a 79 K10 with a new 3 speed heater only fan selector. I recently swapped out the heater only box with an ac/heater box that someone donated. I don't care about the ac right now but only want the heater and defroster to work right now. Here's the problem I have... the fan selector is 3 wire and the resistor is 4 wire. First of all is this even possible to use the non a/c selector switch? I don't want to have to buy another new switch just yet unless I know for sure I will want ac in the future. Currently, I only have the blower motor working when the key is on and the selector switch is on hi. There is nothing on the 1st two speeds. Any help is appreciated.

Re: Heating wiring question
 

:welcome2:

Re: Heating wiring question
 

You can run the non AC resistor and heater control with the heater sub-harness.

AC uses a relay to run the blower at full speed without melting the switch. You'll need to retrofit the AC wiring and relay along with the AC controls.

How are you handling the firewall ducting differences?

Re: Heating wiring question
 

Thanks for your response Hatzie!
That might be a hurdle I have yet to come to. I got the switch to operate correctly. Turn the key on, the blower motor comes on. I also got the blower motor to increase with the selector switch fan speeds respectively. I'm not using the number 4 connector on the resistor. I have hot air but I'm concerned the resistor might heat up to much. Is that possible?

Re: Heating wiring question
 

You should have airflow over it with the blower on. Not sure whether you'll get in trouble without...