First of all, thanks for maintaining this site. I have really enjoyed reading through the threads. I have a problem, that I have not been able to find a solution to.

I am trying to learn some basic auto repair, but learning is hard, and books have so many words (lol- kidding I'm a teacher).

I am trying to fix the small stuff myself, and learn along the way.

So, My A/C is not working. I leave school, and turn on the A/C. It blows warm air. not hot like the heat is on, but ambient air +/- a few degrees. After about 20 minutes the compressor kicks on, and I get beautiful cold air. just like the old days.

As long as I am driving, it is fine, and I pay close attention to it, as I can feel the air on my face, the humidity etc.

If I stop, at a light, for example, and the truck returns to idle (~800 rpm) the compressor turns back off, and I feel the difference in the tempo and humidity of the air on my face. When I move again (green light) the compressor turns on again, and I get cold air.

If, while I'm stopped, and I keep the truck idling ~1k, the compressor stays on, but the second I fall below that, it turns off. At normal idle, the compressor will click on and off every few seconds- and it bogs the engine to ~500 rpm for a second then returns to 800ish.

I am the original owner, no major work has been done to the truck. A few tuneups etc, plugs, thermostat about 2 years ago. I have had this problem (and been kind of ignoring it) for the last 2 years. Last summer, I bought a DIY r134a kit from Wall-Mart, with a gauge. It would not take any, as it was saying full on the el-cheapo gauge.

Car has about 119k on it. And I am hoping to fix this, and learn from it. I have done some research, and looked at many threads, but no-one seems to have mentioned theirs works fine above 1k.

I have read about the:
A/C compressor
Low pressure switch
Relay C1008
fuse.

I wonder if I can rule out the relay and the fuse, as I get the A/C to work? If that is not correct, how can I verify correct operation of the relay? I can figure the fuse out on my own I think- lol.

Thanks for reading this too-long message. I would love some help. I would like to be able to drive "Betsy" back and forth to school for many more years. She is very handy.

dave
catonsville, md
USA

i had a vacuum leak that caused the exact same symptoms. it was under warranty, so took it in, and the mechanic said it was a vacuum line leak. i don't know where the leak was, but he fixed it.

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1999 xlt 2.5l 5-speed Supercab 159k
83 diesel 2.2l na
06 F250 6.0l psd
{click for lol}