A/c questions

[white2Door]

Hello All i am new to the forum. i just picked up my 97 2 door tahoe about a month ago. so far i love it and havent had a problem with it. However when i got it the A/c wasnt working but it was not hot out there yet. But it has been getting verry warm lately and im hating not having a/c! So when i first picked it up it wouldnt blow hot or cold. I noticed the light on the control panel would not come on when i pressed it and the pump wouldnt kick on. so i replaced the control panel and now when i press the a/c button the light comes on i can hear ? feel the a/c compressor clicking on. however it only clicks on for like a second the clicks right back off? Any ideas? i would greatly appreciate any tips and advice , its getting hot out here and its terrible with no a/c. Thanks in advance. Alex

 

[gpracer1]

If the compressor is actually engaging, then most likely you are low on 134 freon. You most likely have enough pressure left when static to make the low pressure switch. As soon as it kicks on however, the pressure will be too low as the compressor sucks it down.
You need to put some gauges on it and it will most likely need more 134a.
This means you probably have a sloooow leak, depending on when it was last charged.

 

[white2Door]

I actually had it charged recently, and it still did the same thing. So im gonna have to put a guage on it and check the pressure. It dose have a leaking shrader valve but the guy at the shop said once the black pastic cap is on its good and should stop the leak? is he full of shit? should i change the shrader valves?

 

[gpracer1]

Hahaha, I just had to replace my high side valve 2 days ago. I went to check the pressures and when I took the cap off, it was hard to turn (under pressure) and when it got 3/4 off, it blew off in my hand and scared the shiat out of me.....ac was on (250 psi high).
Argued with the guy at Autozone that it was not a schraeder, but a ball valve. When he pulled the part I was right, you cant replace the valve core, you replace the whole high side "nut" housing $7.00

You need to hook up gauges and watch the low side and high side readings. It should cycle at anything below about ~23 psi on the low side. If it is cycling at over 30 psi and higher, then the switch could be bad ($15) or maybe possibly the ac controls are bad.

You said it clicks off in a few seconds, so the high side pressure does not have time to trip, unless it is waaaay overcharged or the high side switch is no good.

Gauges will tell most of the story......maybe even orifice clogged.....super low low side, and high high side.

 

[SunlitComet]

Cores are supposed to be replaceable and yes the cap does stop a leak when installed correctly and there is no damage to the fitting. Based on a one second cycling that is a sign of a pressure switch trigger. How long does it take before it re engages? Gauges will really help right now.

 

[white2Door]

im gonna give it a try and change the valves and put guages to the system and see what happens.

Sunlitcomet: When i first hit tha a/c button it will click the pump on for about a second or two but once it clicks off it wont re engage.

 

[SunlitComet]

At all?

 

[white2Door]

yeah it wouldnt come back on at all. Im at work and i just went outside to try it and now the pump wont kick on at all? What do you guys think? i really need to get this fixed asap!... thanks for all the replies guys!