Heater Wiring

[BigSwid79]

Could some please explain to me the heater wiring in a 79 chevy. it is just heat no AC.

I got the box on the fire wall and no wiring to it. I have plenty of wire and knowledge to wire it myself.

I can get power to blower motor and have fan spin, but I don't know what wires come off the box and got back to the switch to break the circuit.

So basically i can get power to it, there are suppose to be wires that go to the switch to break the circuit when you turn the switch to off. Please help with what wires go to what terminals and how it goes into the heater switch

Thanks, swid

[VetteVet]

Well I don't know when they changed to the newer resistor but the wiring will be pretty much the same as the 67 - 72 trucks. At least you can get an idea from them.

Basically there is a 24 gauge brown wire from the fuse panel heater fuse that runs to the heater switch to the main 12 volt terminal. See the diagram below.
It comes out of the fuse panel on the lower right and loops to the left up and to the right to about the middle of the page on the far right.



Pick it up on the diagram below and follow it up to the heater switch on the upper right. From the heater switch you can follow the blue yellow and orange wires to the resistor. Then the orange wire from the resistor goes to the fan on the firewall.




Here is the typical resistor and the wiring to it from the switch and the orange wire from it to the heater fan.




Your job will be to locate the resistor. It is usually inside the metal housing under the dash behind the heat door. you may have to take a duct hose off to see it.

I found this.

http://67-72chevytrucks.com/vboard/s...d.php?t=427775

[Gail]

Thanks I will let you know how it turns out , this is great THANKS
GAIL
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[motornut]

my 79 has the resistor under the hood
power comes from connection top right of speedo
some are wired the low speed always on(i cut the brown wire)