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My 2002's AC intermittently blows ambient air. I cannot find a pattern.
I checked the pressures at 80F ambient and got the following which according to a generic temp/pressure chart, is on the low side, especially for the low side port.
Should I slowly add refrigerant until the values increase? Maybe the pressure switch is cutting the system off when pressures drop too low?
If you want to be absolutely sure of the correct fill: drain, flush and vacuum the system. Then fill to the correct refrigerant quantity by weight. Maybe let the system sit for half a day at full vacuum to see if there are any leaks first. If you really want to go all out, replace the orifice tube with a new one. They tend to get plugged with gunk.
I would probably start with the compressor clutch. The age these trucks are getting too be it's hardly unexpected for those kinds of things to start needing attention. There is a spec for the gap between the clutch disc and pulley. I'm wanting to say it's something like .080-.120 but not 100% on that. If it is worn or out of spec there is a shim that can be removed under the clutch disc and buy yourself another season or two. I'm pretty sure the spec and the shim procedure can be found in the tech section. I'll have a look and see if I can find the links.
Edit: Found a link for a video with the clutch information that should work.
Sounds just like my truck 2 years ago ended up replacing clutch and all is well the magnet was getting weak. And dropping off when it was warm clutch air gap was correct as well.
Sounds just like my truck 2 years ago ended up replacing clutch and all is well the magnet was getting weak. And dropping off when it was warm clutch air gap was correct as well.
Maybe a new clutch is in order.. would be a better option than needing to pull the refrigerant out to put in a new drier or whatevs.
Those pressures look pretty normal to me. If they equalize quickly when you shut it down that means your orifce tube is probably not plugged either. Does it happen while stopped or low speed or while moving? If it happens while moving I would guess the compressor clutch might be letting go intermittently. When I had no fan on my truck the A/C would still blow cold going 35+ mph but would go warm pretty fast if I came to a stop. All that to say I wouldn't suspect a lazy fan clutch unless it was only happening while not moving or in stop and go traffic where theres not enough natural airflow going across the condenser.
Thanks for your thoughts. I didnt test equalization...but I will.
It happens when Im on the move or idling. It randomly stops blowing then starts again minutes later
Why did you have no fan on your truck????? I only have the huge clutch activated fan. I dont believe I ever seen a separate AC fan come to think of it.
There isn't one, well unless someone added one out front of the condenser. Which isn't uncommon I added a couple myself to help keep the ac blowing coldish at idle on the crazy hot days. Those and some functioning fender vents to help with engine bay temps made a noticeable difference.
