Compressor runs continuosly but doesn't blow cold.
 

Compressor works continuously but doesn't blow cold. Hooked up the gauges to the low and high ports and I get the same 80 lbs on both. It won't let me add freon as well...no suction. Weird, huh. I'm thinking expansion valve is stuck...any ideas and do you know the schematic for an 07 F150 V8?

Sounds like the compressor is not working if both sides have the same pressure. Are you sure the compressor clutch is engaging? I doubt if you have an expansion valve. Ford went to fixed orifices way back as early as 88 that I know of. But, I can't speak for a 2007.

You need to take it to a professional.

Thanks Roadie! I didn't think that it had an expansion valve, but that's what kept coming up in troubleshooting. I'm certain that the compressor is working...you can turn off the AC and it stops and then turn it on and it starts right up, constantly, but no cold air. I'm wondering if I vacuum the system and recharge that it may work...just a thought.

Truck only has 60,000 miles on it and what's weird it has always worked great. I traveled about 30 miles blowing cold all the way...went in the store and came out to hot air. System is pressurized for sure.

If the compressor is running, the high and low side pressures would not be the same unless the compressor is completely kaput. If that were the case, it seems it would be making funny noises. If it is running and the orifice tube is plugged, the high side pressure would be too high. There may be a high side pressure switch that cuts the compressor off. But, you say the compressor is running????

The door (blend door?) that controls the air routing could be working wrong to divert the ac, but that wouldn't explain the high and low side pressures being the same?

Take it to a pro!

I doubt that the compressor is actually running.

OK, thanks for the tips Roadie. Just to be safe and start off cheap I vacuumed the system, checked and cleaned the orifice tube (it was very clean...just a couple of metal shavings, oil was clear) reinstalled and charged the system to 150. I'm still getting 150 on both sides though and no cold air. The clutch is engaging so I'm assuming the compressor is working? Everything is quite and no leaks detected. Not real sure what to do other than maybe replace the compressor at this point. I've never, ever taken anything to anyone to be worked on in my 54 years of life and I don't plan on starting now. Gonna get a book on the model and go from there. Thanks a ton!

I hope I've helped but I'm no expert. I've repaired auto ACs before and learned enough about them to fix my problems. You have a strange problem. Please let me know what it was when you find out. I'd really like to know.

Could there be something wrong with your gauge set?

I'm thinking that the compressor is just spinning it's wheels and not doing anything. The only time the clutch cycled was when I was recharging it and after that it just keeps on going...doesn't even make any chirping or anything. Hoping that it's just the compressor...pretty easy swap out.

If you measure the same pressure on both sides, either the compressor ain't compressing or the gauge manifold is leaking between ports.

Inspect the CENTER BOLT to see if it's rotating, not the clutch hub itself.

if the clutch and the pull is turning together,shaft inside compressor could be broken? should never have to same psi reading when running.

That's kinda what I'm thinking now RevBiker. Funny that it's not making any chatter or grinding though. I'll replace it and let ya know. Thanks all! :)

Funny that there's no trash in the lines as well...clean as the day it was put in.

Guy at Autozone says it sounds like the valves are blown in the compressor. Everything would still work...just won't blow cold. I'm going to try to pick up a new one over the weekend.

RevBiker...you hit the nail on the head Brother! Got my parts in yesterday....replaced the compressor and all the normal crap with a major rebuild, vacuumed, charged and presto. Tore down the old compressor and you were correct...broken shaft. Can't believe it went kaput with only 60,000 miles. I've had vehicles with several hundred thousand and never a hick up. Thanks for all the responses and now I'm driving cool in Texas 105 degree heat...WOOOT!