After swapping all the wiring and interior from my 99 to my 97 i was going to charge my a\c but the clutch will not kick on. i didn't even feel the relay click. The clutch doesn't kick on for either the 97 or the 99 but it used to work on my 97 before i swapped everything. im pretty sure i had to change both the high and low pressure switches so the system was completely emptied on my 97. i did go ahead and spray a little bit of r134a into it to see if it would kick on but it didn't so i gave up. the only thing i have tried is swapping a relay for a known good and still nothing. any other ideas from anyone more familiar with the a\c systems would be greatly appreciated.

 

Try jumping both the low/high pressure switches.

You'll have to evacuate the system before charging.

 

How do i jump the switches? Just one at time or both? I had to chenge both because the connectors were different, with both out was the system not evacuated?

 

Use a piece of wire.

Odds are it's the low pressure switch so try that first. The clutch won't engage if it's low on refrigerant.

 

Tried jumping the switches and the idle changes like the clutch kicks on but it doesn't actually move. I did notice two small leaks after turning the engine off. Could those leaks keep it from kicking on?

 

Low pressure will keep the system from running so if you're leaking...

Try jumping the clutch directly from the battery. It could have failed. You should see the inner part of the clutch turning when engaged.

 

I think I fixed the leaks so that cant be an issue anymore. When i jumped the low pressure switch the truck idled up like the clutch kicked on but nothing. When I plugged the switch back in it idled up the same way but still nothing. If i unplug the relay and plug it back in i can feel it click and turning the control switch to air or defroster the truck idles up but still doesn't kick the clutch on. I can turn the clutch by hand so it's not stuck. I will try jumping the clutch to a battery and see what happens. Does the battery have to be 12v?

 

I tried jumping the clutch to the battery and nothing. Does the truck have to be running? I tried jumping the clutch on the 99 and it clicks. Im guessing that's the next thing ill be swapping around.

 

Got the compressor swapped and put enough stuff in to get the clutch to kick on. Now it kicks on for about 2 seconds then back off. While it is on, the crappy little gauge for the can of r134a drops almost completely and while the clutch is off it sits wherever i stop putting more in at. Right now that is in the yellow "warning" area on the gauge past the full area. It is not blowing even a little cool inside the truck. Is there something i can do to get it working right or should i leave well enough alone and take it to a "professional"?

 

The clutch is cycling due to low pressure.

Did you evacuate the system? Put a vacuum on it to remove the air and moisture? You can't just fill it from a can once it has been opened.

Take it to a pro.