AC clutch problems?

[BLAZERMAN]

When I turn on the ac in my 72 the compressor clutch does not kick in. I have hot wired it directly to the battery and it works fine. Where should I look first, the switch? or is there a relay or fuse somewhere that should be checked also?

[Aarons72s]

Id check the plug on the compressor or the switch for the clutch inside first. The switch is on the back of the diverter box, the box all the hoses in the cab come out of. I f you reach behind it you should feel it. Check those 2 things first.

[71Rat]

if your getting power from your switch to the compressor and the compressor isnt kicking on but it works with 12 volts to it the clutch head is actually going bad. if the switched side is getting 11 volts to the clutch then its just old and tired.
if your not getting power then start tracing things back to see where the problem is. power before the switch? blown fuse? bad relay?

71rat

[chipflyer]

Rob,
Take a look at the diagram below. With a test light you should be able to figure out where the problem is, most likely in the fan switch. I had the same issue with mine several years ago when I put the AC back together but I can't remember exactly what it was. The compressor clutch is a simple magnetic clutch it will either work or not and you have ruled that out by jumping it.

Good Luck!

Jeff