Wicked500R

I installed a new AC compressor yesterday and the clutch did not engage in the AC positions or heat positions. There is some kind of sensor or switch with wires going to it on one of the AC lines, I was wondering if it is a pressure switch that will prevent the compressor from kicking in if there is nothing in the system.. anybody know ?

Busboy

The system IS protected by Hi and LO press sw's.

sheriffav8r

The pressure switch is on top of the bottle on the passenger side firewall and it will prevent the compressor from kicking on if the 134 is low.

nickg

likely you are low on freon, you can TEST your clutch by running the truck unplug the switch and jumper it, if the clutch engauges the clutch and wiring is fine, but likely your low on 134 or the switch is bad, best to have the pressures checked, over filling the system is worse than not enough.

duner

he said there's nothing in it.

nickg

he said "IF" there was nothing in the system, he did not say the system was empty

Wicked500R

The system is empty. Thanks for the help !

nickg

was it empty when you asked? if it was I retract my previous statement to Duner, my apoligies, I re-read the first post and now notice(I missed it) that you replaced the COMPRESSOR, which would mean the system would have to be empty, you had it evacuated right? and after removing the AC compressor QUICKLY replaced the compressor, so that the system was not open to moisture( the Dryer will suck moisture out of the air, effectively ruining the dryer and causing ac issues later , ie freezing up/poor ac performance)

Wicked500R

It was empty when I asked. The job to replace the old compressor was not easy. 20 minute job turned into a whole weekend! 3 bolts snapped off with the studs still through the compressor and the compressor was frozen in place. Even with Snap-On's baddest air hammer and healthy doses of PB Blaster ,it would not free up.. I ended up having to break away the compressor housing around all the remaining bolts with the air hammer to get it out. And the I still could not get one bolt out, so I had to bolt the new compressor in with only 3 bolts. The truck did sit with the system open for a day. I didn't have a choice while trying to the broken bolt's out...

Busboy

If you live in an area of high humidity I would consider changing the drier, if not then leave the vacuum pump on extra long and ensure the vacuum is 29-30 inches. This will boil out the moisture. Then close the gauges and make sure that the system holds the vacuum. It should NOT drop any, if it does you have a leak. A leak will show better with vacuum than with it charged.