'93 S10 Air Conditioner...no worky. Is there a low Freon disable??

[87LtdT]

A guy tells me that maybe if freon level is low the AC will be disabled. I know for sure there is no voltage change at the AC coil when I turn AC on or off.

AC fan works fine...but the clutch never activates.

Any tips??

Thx, Bob

[Steve Wood]

should be a low pressure switch on the can...you should be able to pull the connector off and stick a jumper between the terminals in the connector and see if the compressor starts...don't leave it connected if it does start until you figure out if it has no freon in it or the switch is bad.

[CallMeMud]

I just posted yesterday on the S-10 board about the same thing on my S-10. I jumped the plug and the compressor worked but I also put a gauge on my system and the pressure was low. I put the plug back on and charged the system with one can of 134 and it started functioning normal off the switch. My compressor will still not stay on 100% so I have to get someone to find the leak. On my gauge the compressor kicks out at 15 PSI and on at 25 PSI. This is how I know the switch is working.



Steve,


You have an e-mail.

[87LtdT]

You guys talking abut jumping the electromagnet connector on the freon compressor unit?? Or a switch on the cannister....which I haven't seen yet.

So the anwer to the question is "yes...there is a low pressure detecting system that can cause AC to not work."

What is S10 board adress??

Thanks Sirs, Bob

[CallMeMud]

The pressure switch is on your dryer near the firewall. I jumpered sides at the plug. If your switch is working correctly it will keep the compressor from coming on when the system pressure is low. Best thing to do is buy a charge kit with gauge. If the pressure is 30 PSI or lower add one can and see if you compressor starts working. Put the can in a hot pan of water to keep it flowing out (head pressure). The S-10 board:

http://www.s-series.org/

[BuickGN Boosted]

That's weird! Tried out my AC today for the first time this season on my 96 Blazer and nada. Compressor won't come on. Worked fine in the fall. Always something!

[CallMeMud]

Check that schrader valve at the the receiver. I had my system sniffed two days ago and the schrader under the black cap was leaking. I have a replacement now so I just have to find time to pull it out, replace with new, pump the system down and recharge.

[87LtdT]

Hey Mud can you be more specific as to where to jump?? There is a wire coming into the top side of the "can"...do I pull that wire off and jump it?? Or is it some other wire??

And which side is the low pressure side...and can I check pressure with a tire gauge or do I need something special??

Last time I observed my AC clutch working it would just cycle on and off....wouldn't stay engaged much more than 2-3 seconds...sound like low freon?? Of course now it doesn't come on at all.

Thanks, Bob

[CallMeMud]

Originally posted by 87LtdT
Hey Mud can you be more specific as to where to jump?? There is a wire coming into the top side of the "can"...do I pull that wire off and jump it?? Or is it some other wire??

And which side is the low pressure side...and can I check pressure with a tire gauge or do I need something special??

Last time I observed my AC clutch working it would just cycle on and off....wouldn't stay engaged much more than 2-3 seconds...sound like low freon?? Of course now it doesn't come on at all.

Thanks, Bob

I went out just now to get pics for you. It actually makes zooming in easier doing in the dark with a flashlight. You need a Max-Effort on your Buick then that pressure switch would be second nature to you Okay.... A/C 101...


Here is a picture of the switch with the wire connector coming off of it. You take it off and jump one side to the other. Use a paper-clip if you don't have anything else.

[CallMeMud]

You can try the tire pressure gauge but I doubt if it will work. You will need the line and 134 to charge the A/C anyways so buy the $40.00 kit that comes with three cans of 134, line and gauge. You will waste one can when you charge the system to find the leaks. That leaves you two cans to charge it when you have it repaired. Here is the low-side port where you check pressure and fill. It is on the opposite side of the pressure switch:

[87LtdT]

Thanks Mud...now let me tell you an embarrasing story.

I had already jumped that connection but got no response from the compressor clutch. So I sent my note asking for more detailed help..wanting to be sure I was checking the correct connection. Late last night it dawned on me that I had not turned the AC "ON". This morning rechecked with AC "ON" and the clutch worked like it should.

Don't tell anybody about my supreme dumbassness....OK??

I have a few cans of R12 and I'm going to add 1 or 2 without addressing the leak...will see how long it lasts.

Thanks again, Bob