Help with wiring...

[gagraphics]

Hey peeps... Let me start by saying sorry, as I know there are a lot of threads out there regarding heater wiring, and I have been using search function and have the diagrams, but I still a little confused.

Can someone help me by explaining what relays I need to use, and ones I dont, and How I should go about wiring the ones I need together? I have 72 stepside with Ac but do not want ac to work, just heat. I have ordered most new relays and connectors, but I am not sure how to wire them all together!

Like the compressor switch on the back of the heater tube box, do I even need that if im not hooking up ac? the resistor that is inside the box and close to the heater core, how do I wire that, cause I cannot find a connector for it on LMC.
I have ordered the a/c blower relay and connector, as well as the fan controller wire connector. Anyone that can guide me in the right direction, I will appreciate!

[VetteVet]

I would refer you to this thread, It may help. I don't believe there is a relay just the resister.

http://67-72chevytrucks.com/vboard/s...d.php?t=689364

[gagraphics]

Originally Posted by VetteVet

I would refer you to this thread, It may help. I don't believe there is a relay just the resister.

http://67-72chevytrucks.com/vboard/s...d.php?t=689364

Vettevet, you were one I was hoping would chime in as I have seen you are very knowledgeable... I will check out this link.

[dmjlambert]

You have an A/C truck, so there is at least one relay for high speed selection of the blower motor, and since it is a 72 there may be another relay for anti-dieseling (which is probably not needed. So, follow the wiring diagrams for the four seasons A/C which are in the service manual.
Service manuals:
http://67-72chevytrucks.com/vboard/s....php?p=5781194
Threads with A/C wiring page from service manual, both with and without anti-dieseling relays.
http://67-72chevytrucks.com/vboard/s...d.php?t=727010
https://67-72chevytrucks.com/vboard/...d.php?t=807883

[gagraphics]

Originally Posted by dmjlambert

You have an A/C truck, so there is at least one relay for high speed selection of the blower motor, and since it is a 72 there may be another relay for anti-dieseling (which is probably not needed. So, follow the wiring diagrams for the four seasons A/C which are in the service manual.
Service manuals:
http://67-72chevytrucks.com/vboard/s....php?p=5781194
Threads with A/C wiring page from service manual, both with and without anti-dieseling relays.
http://67-72chevytrucks.com/vboard/s...d.php?t=727010
https://67-72chevytrucks.com/vboard/...d.php?t=807883

Yes, my truck has A/C, however, I would like to wire around ac compressor switch as non of the a/c components work and dont plan to fix right now. Maybe later... So it does have one relay, but I am not sure I see the second. The one I can see is located by the passenger foot panel under the glove box. I am guessing this is the control switch relay for the blower. I got this diagram from Painless... and ordered connectors from LMC. Wire colors match to controller connector, but the relay connector has black, yellow and white wires. Not even close to what Painless says... THOUGHTS?

[gagraphics]

ALSO!!! anyone know where to buy the connector for the resistor, or should I just wire without connector? Can seem to find on LMC!

[dmjlambert]

Do you have a painless wiring harness and that is why you are using diagrams from painless?

[gagraphics]

Originally Posted by dmjlambert

Do you have a painless wiring harness and that is why you are using diagrams from painless?

that is correct. I ended up this morning ordering the heater/ac harness, so everything should just plug right in.

https://www.painlessperformance.com/Manuals/30901.pdf

[dmjlambert]

Good, let's see if they live up to their name.

[gagraphics]

Originally Posted by dmjlambert

Good, let's see if they live up to their name.

So far I have been very happy with it. Manual for main harness is very descriptive, and all wires have numbers and labels on them. Making its easy to find the ones you need. I'll update on this post when I get the heater harness. But from pictures, looks like everything is there and I just need to plug in... Now just praying my heater core is not leaking!