[Simple10]

Originally Posted by Andy4639

The AC in these trucks is wired totally different from a heater only truck. Is the truck a factory AC truck are did the PO install it??? This could be your problem. If he hooked it up without the correct wiring & components.
The AC trucks have a few more parts to them. The fuse has to be swapped as well.
This link shows the heater only schematic not the AC. It is a great schematic and I refer to it often.
http://67-72chevytrucks.com/vboard/s...185856&page=16

I use the breaker fuse instead of the normal 25 amp fuse. It will heat up and kick off then cool down and come back on. You need to get power to the switch first though.
You stated in your last post you have the AC back running.

It want run unless you have the fan switch set to at least the low setting if this is correct then you have power to the switch. ????
Also you said


This could be the problem. Have you verified the wiring is correct? The wires could be placed wrong.

That was me who said the plug fell off, when I took the resistor out and replaced it (which done nothing) the weight of it made the plug on the back fall off that’s why I had no cold air.

And when I flick the fan switch to low or medium it doesn’t work but you can hear the aircon click in , so I’m hoping it’s a crap switch now on medium and low, high works fine.

The auto electrician said the switch is fine, Don’t believe him yet. Stay tuned .......