jcy110

Original 2001 Tahoe owner 220,000 miles- I start the Tahoe and the air runs nice and cold, sit around for a while and the compressor cuts out warm air blowing...... I drove on Rt 80 for 200 miles no problem, ride in town stop and go A/C compressor cuts out.....warm air blowing. Last night I changed the clutch fan. Started it today and left the hood open, nice and cold for hours, close the hood, after a while A/C compressor cuts out. Leave the hood open and checked it later and the compressor was back on blowing nice and cold. NO I CANNOT DRIVE WITH THE HOOD OPEN UNLESS I CUT A HOLE IN IT...LOL Any ideas??????????????

73shark

Is the fan clutch engaging when the hood is down and vehicle is stopped?

Check the A/C pressures when the compressor shuts off. If the fan isn't running and pulling air thru the condenser, the high side pressure will increase and trip the high pressure switch.

jcy110

I will let it idle with the hood down and when I feel the duct air go humid and start to warm I will open the hood and see if the fan is locked. I will report back.

I let it warm up until the A/C cut out. Opened the hood and the NEW fan clutch I installed 2 days ago is not locked. I guess it means that it is hot enough to make something open in the A/C circuit but not hot enough to make the fan clutch lock. It is 66 degrees right now outside in NJ.

jcy110

I let it warm up until the A/C cut out. Opened the hood and the NEW fan clutch I installed 2 days ago is not locked. I guess it means that it is hot enough to make something open in the A/C circuit but not hot enough to make the fan clutch lock. It is 66 degrees right now outside in NJ.

I know a guy who has A/C gauges, I will take it to him and let him see if anything looks suspicious. Thanks for the suggestions.

73shark

The pressures will tell you if the freon charge is correct. Too much or too little can cause the high or low pressure switches to open.

And if the pressure increases or decreases to the point that the compressor shuts down, then you'll know.

What's the water temp. when fully warmed-up?

jcy110

The water temp gauge reads 195 F when warmed up.

jcy110

So the bottom line at this point was the low pressure switch went open electronically on getting too hot not mechanically from low pressure. I brought the Tahoe to my cousins, the A/C had already cut out. He put the gauges on and (if I remember what I saw) without the compressor running the low side was 50 and the high side was 100. He took off the low pressure switch connector and jumped it out. INSTANTLY the A/C came on....he plugged it back on the Low Pressure Switch and the A/C cut out. I went to Autozone and for 21.00 got a new low pressure switch. We unscrewed the old one and put on the new one......WA LA.....the A/C turned on and ran cold at idle. I closed the hood and let it idle for another 1/2 hr while we were talking and the A/C compressor ran the whole time and never got warm or cut out! At 1500 rpm the low side was 80 and the high side was 250. The A/C condenser is hot now making the clutch fan engage like it should to move more air. When I left his house I could hear the locked fan roar for a while.

I hope this helps someone else because there wasn't a low pressure issue, so why check it when you have a problem when the engine compartment gets hot and points to a high pressure issue..........the Tahoe is a pleasure to drive once again!

73shark

Thanks for reporting back on your solution. Glad you got it fixed.

jcy110

Well................it ran ok for a few days, the compressor stopped running today. I jumped the low pressure switch connector, A/C came on immediately so I taped it up. Can anyone tell me what the GM part number is for this low pressure switch? Or post a link. The switch I purchased last was from Autozone. I have a 2001 Tahoe 4X4 LS 5.3L I have looked on many websites, most don't even have a listing for it.

73shark

Might try your Chevy parts dept. I'll try to look in my parts catalog.

Forgot that this was the Tahoe forum. My parts catalogs are Corvette.