New to me 2004 XLT 5.4L with 57k miles. Since I bought it the A/C just hasn't seem very cold. Threw a thermometer in the vent and have been monitoring it for the past week. With A/C on MAX and blower on 4 I'm getting temps from 60-70 with outside temps in the 80's. Could be worse, but obviously not ideal. The weird thing is I'm getting colder temps both with the blower set lower and when I'm idling compared to running the truck under a normal load. With the blower on 2 and at an idle I'm getting temps around 50 and a bit below. Any idea why I could be experiencing these symptoms? The compressor is operating normally, from what I understand. It runs constantly when I have the A/C set to MAX and the blower on 4. With the blower on 1 it kicks on and off. I followed vacuum lines and checked for leaks under the hood the best I could (read vacuum leaks to the system could cause my symptoms), and all checked out. The high side line is piping hot and the low side line is ice cold with condensation when the system is running. Both, I believe, are normal for a functioning system. There is what looks like fresh yellow dye on the low side port indicating it was recently checked for leaks. I'm assuming it was serviced shortly before I bought it from the local Ford dealership. Any other things I should check? Thoughts? Maybe just an old and tired system on a 15 year old truck?

 

You need to take it to a pro. It could just need a recharge.

 

My '04 Lariat (with 250,000 miles) has similar symptoms to yours. When I had the oil change done 2 weeks ago (at my local Ford Dealer) I asked 'em to check it out. They told me the A/C compressor is kaput. The estimate I got is $750 …

Sad potato is sad …

 

Yeah, that's what I'm afraid of. It was nice and cold this morning with ambient temps in the high 60's/low 70's. But when it gets up into the 80's/90's I get what I described above.