Brand spanking new ac compressor, new orfice tube, accumulator deal, new ac connector deal.
Got the gauge set and a vacuum and vacuumed the sucker out really good, tested for leaks and all was good. Went to add freon and it wouldn't take much before the low side exceeded 45 psi and the compressor still didn't engage. I've been googling and playing with this all day found out there is no power going to the high side pressure switch. And my vacuum pump doesn't turn on and no power going to the compressor connector replaced that harness too. So kinda stumped, maybe it's a relay? All the fuses are good.

 

Swap the ac relay with a similar relay , like the horn relay . See what happens then .

 

Nothing seemed to have changed. I've swapped out several relays to make sure.


The larger red wire that goes to the vacuum pump has power. But all the other wires that run along that run to the low side switch and high side switch and the compressor connector do not have any power.

 

The pressure switches are in a series and both need to be closed to send power to the a/c clutch. Recently another member had similar trouble and found it to be at the low pressure switch connection. You say there is no power to the low pressure switch?

 

I do not get any power to that connection. The connection does seem a little iffy. But I have connected a meter up to the connection and to the connection where it ties into the main harness and the wire is good. I'll do more trouble shooting towards all the connections later today. I'm sure it's an electrical issue somewhere. This truck has been kinda rebuilt and has a lot of weird issues, like the horn don't work, only the high fan setting works for the ac/heat all the other settings are just a low setting. The cruise control don't work, little odds and ends like that. But I don't know if the ac clutch ever worked or not. Just knew that it didn't work and it was never turned on for a long time so I just replaced everything.