Hey guys, I have a '99 half ton 5.9l with 4wd. My AC system was low on refrigerant and the AC clutch was not engaging. I added a small amount of refrigerant and the AC clutch began working (although it cycles on and off every few seconds, not sure it that's normal or not), but I still get ambient temps blowing through the vents. Pressure on the gauge looks good, where do I go from here? Thanks.

 

did you check the high side also or just the low side?

 

If the compressor cycles on and off every few seconds, you are still low on charge.

 

I need to charge mine up and see what happens, i havent seen my clutch kick on at all, ever. I dont know if it works or not even

 

I only checked the low side because I was told that checking the high side would wreck the gauge. I just bought one of those ACpro recharge kits with the gauge attached. The gauge bounces around quite a bit when the clutch engages. It reads very low when the clutch is not engaged, but as soon as the clutch kicks in the needle shoots up into the red part of the gauge, then drops back down as soon as it disengages. Any clue?

 

You have a major leak. I'm going with evap core.

 

Sounds like its low.

 

Figured it out, I guess I just needed to keep adding refrigerant. AC works ok now, but it's not nearly as cold as it should be. I guess we'll see how long it takes to get low on refrigerant again and go from there. Thanks guys.

 

You didn't figure out.

 

Might not be pulled correctly, you will have to pull a negative on it or have some one do it for you.