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SDWA
03-28-2007, 16:45
My 2002 has 130K miles... and it's first real problem (other than having all 8 injectors replaced...) has cropped up: The A/C doesn't appear to be dehumidifying anymore.

I noticed the other morning, at a crisp 35 degrees out, that it's not clearing the inside of the windshield anymore on defrost. Not that it instantly removed ice or frost before, but at least there was no fog on the inside. It quite a challenge to drive down the road and use a paper towel to clear a small portion of the inside of the windshield, before the engine got around to providing some heat to dry it off the old fashioned way.

It used to be anywhere, anytime of year, it'd dump a quart of water on the ground after I parked it. "Your truck's leaking..." I'd hear that all the time. Now that appears to be gone too.

I can't tell if the A/C is up to full strength, because the ambient outside temperature isn't but around 50-55 or so. It feels cold, but then again, it feels cold outside too. The compressor clutch kicks in and out, as normal, at least like what I remember normal to be.

Is this a symptom of low refrigerant charge? Bad low pressure switch? I'm working on getting my hands on a A/C service manifold so I can check the system pressures, but any ideas before that would be helpful...

Thanks!!!

MikeC
03-30-2007, 00:24
Another reason for humidity inside is "recirc" being activated.

But you've checked the settings but I'm taking a stab in the dark.

Mike

SDWA
03-31-2007, 09:53
The HVAC controls -supposedly- won't allow recirculation mode when defrost is selected, it'll blink the button and reselect fresh for you... but on a side note, the damper is working correctly.

I did find an interesting notation in the service manual that says the A/C compressor won't engage if the ambient outside temperature is less than 38 degrees. I might be tempted to suspect this was the cause, but this was the first time I've had this problem, and it's defrosted/defogged at temps lower than that before... next time it's cold and it's not working right I'll have to pop the hood and see if the clutch is actually spinning!

Scott

SDWA
04-05-2007, 18:21
The system had a low refrigerant charge. It's back to normal, we'll see how long it stays that way, or if there's a leak somewhere.

Anyone know if the system gets dumped when the A/C compressor is removed? I'm assuming they had to remove it when the injectors were changed... and that might be the source of a leak.

Scott

madmatt
04-06-2007, 09:14
They shouldn't have removed it to r&r the injectors but yes, the system must be evacuted to remove the compressor.