don't always believe PO's - more AC diagnostic stuff

[srplus]

my PO and his PO told me (and their PO told them) on the AC question that the car had not been converted over to R-134A... WRONG!!!

was doing the diagnostics yesterday on why it did not cool and there they were, the R-134A adapters. so the truck had been converted. and it was slam full of the stuff... my problem is that the positive wire to the compressor was not providing any voltage when the AC system was turned on. it was just sitting there - freewheeling... when i disconnected it at the plug and jumpered it straight to the battery it was like a fridge inside the truck. now it is time to do the diagnostics to find out why there's no power up there. i have power at the fuse and the AC button lights and all the other electric in the system seems to be ok. i guess i am just gonna have to track it down by hand one inch at a time with the wiring diagram or just pull a new wire... it’s either that or i have to start carrying around a jumper wire to hook up when i want to run the air… not my kind of solution.

any quick tips or something to look out for that should be obvious or you found already? i know i don't want to punch a bunch of holes in the wire to see if there is a break somewhere. lots of electrical tape to remove unless i get lucky (as if not having a leak and a full system is not luck enough). new wire looking better all the time.

 

[GetsUThere]

On my '40 there's a pressure switch in the AC lines in the engine compartment. The wire to the compressor goes through that switch so that the compressor doesn't engage if the line pressure is out of spec. One of those wires being off caused mine to not be working when I got it. Assuming this exists on a 60 as well, you might want to start there and see if you've got power that far.

Also on the 40, (don't know if it applies here or not) there's a wire from the coil to the AC controller that disables the AC compressor at idle. It doesn't kick in unless the RPMs are over a certain limit.