1994 F150 302 5.0L
Hello, I've been battling my AC lately. I've had the system checked and cleaned with new orfice tube and tech seems to say that pressures are ok. My AC gets really warm at idle on stoplights. It gets decently cool when I am on highway. My AC compressor is constantly on. It does not cycle. The clutch is always engaged when AC is on. My freon levels are correct. I've replace the fan clutch with a heavy duty one and cleaned outside of condenser. When it is cool outside...the Ac works like a champ, but when it is hot outside, 95% of time here in south texas, the AC works badly. The AC tech is clueless and guesses it could be the compressor. Any clues on what could help. He tells me that the ac is always on because it is not getting to efficient temperature to turn off so something is gotta be wrong.

Any help would be greatly appreciated. Thanks
CB

 

How hot does it get? I mean, when you stop at a light, its normal for the temp to go up, ESPECIALLY if its not on recirculate, a brand new truck will do this. If mine is not on recirculate, you can expect the temperatures out of the vents to get to 65-70 on a 95-100 degree day.

 

Ya...during the day it gets pretty warm....when i hit stoplights...then when i take off it gets cooler but never cool enough to compensate for the warmth for the next stoplight/idle.

Today, I took it to yet another tech and he said that my orfice tube was clogged and accumilator. I had those replace four months ago and i said i didn't think that was it, but he was convinced. So i went and bought them new and he installed with new 134a and it was the same as before. $150 dollars down the drain....again....At night time....the ac gets really cold, but during day...the ac is warm especially at idle... Its 100 degree weather down here...and the ac gets warm enough at idle to just rather leave windows down. I wish i could fix this...my lady and i don't like the heat.
CB

 

Where are you located? Its been over 100 here as well, at least on the pavement. I still think you have a compressor issue or a low charge issue. As much as i hate shops, it might be worthwhile to bite the bullet and let them overhaul or fix it or whatever. that way, if they DO something and it doesnt work, they can do it again to fix it at no charge. The way you are doing it is going to cost a lot of money. id make that guy give your money back.

 

Well...found yet another shop...but this time an actual specialized AC shop. Their primary work appeal is ac work. I told him what was going on...right away he said fan clutch... I said i replaced it. Then he said..."with a crappy autozone one" I said a hayden heavy duty...He said that i needed to get a motorcraft. Either way, he said they would check it out for twenty five bucks, so I said please check it. They spent an hour and a half on it and he gave me an $1,150.00 estimate. I was like...that crazy...But he told me what they would do, and that i should do it on my own.

He said the compressor is weak. The low side is 60 and the high side is 225. He recommended i get a new compresser and clean he evaporator. I'm thinking about this now... Sounds good?
cb

 

Get a second opinion. Get one at the ford dealership even. Ive never heard of a 'weak' compressor. You don't want to drop that kind of cash on one person's opinion.

 

I've seen "weak" compressors. The internal valves gum up or fail so they don't seal properly. However, a weak compressor will show low side readings that are too high and high side readings are too low (insufficient pressure differential).

That said, I'd suspect the system is overcharged (depending on what the ambient testing conditions were).

I'd also be suspicious of that Hayden fan clutch...or other condenser/airflow related issues.

Steve

 

How old are the a/c hoses. I've seen people spend hundreds fixing and a/c only later to find out that the hoses were deteriated on the inside stopping up the system, especially the suction line. Hope this helps