A/C not working

[BB]

My '03 GT just started having trouble with the AC.

The compressor cycles on and off and on and off etc. Gauge goes high when the comp comes on and goes low when comp goes off. The on/off happens about 2 secs each way.

Could this be a switch problem?

Any pics of where the switch is located?
Thanks!
Bill

[CREWZIN]

BB,

Sounds like you just might be low in A/C coolant (R-134?) or whatever they are using nowadays. If your low, you won't have enough pressure and the Pressure Switch will keep turning off the compressor. Check that first.


The switch is located on top of the silver canister near the firewall.

[dexadel]

Originally Posted by slartyblarfast

More than likely it is the clutch cycling switch. It is the switch on top of the drier. Disconnect it and then jumper the connector. It's ok to do. That's how I test them. If the compressor comes on and it blows cold then replace the switch. It's a simple on and off repair. Very common problem. Your system may be over charged also. I would take it to a dealer or an a/c shop and have them evacuate and recharge the system. At the dealership I work at we charge about 80 bucks...

Quick question- probably a dumb one, but oh well. I'm learning.

Is the drier the same as the accumulator? If that's the case, is the clutch cycling switch the same as the low pressure cycling switch? I couldn't find anything in my book about the drier- or clutch switch. I've read up on the low pressure cycling switch being a common problem. Is this what you're referring to?

And dumb question #2- how do I jumper the connector? Where's the best place for getting juice to the connector? Battery?

Thanks for your help!!

[CREWZIN]

I think the only switch is the one on top of the silver canister (Accumulator/dryer?) in the picture above.

The way I jumped the switch on my Vette is: take the connection off. This leaves the switch with two small connections. Bend a paper clip in a "U" shape and attach it to both connections that are still on the switch so they will stay there when you let go of the paper clip. Then start the car and turn on the air condition to see if it works OK. If it does, you need a new switch.

Or, if the "U" clip won't stay on, turn the engine ON and the air-conditioning ON and then go and hold the "U" clip onto the the connections of the switch and ask someone in the car to tell you if the air-conditioning is cold.

[BB]

Thanks mucho CREWZIN! The pic helps a lot!!

I'm showing full on coolant so that's not it. I'm hoping it's a switch problem at this point. Being in S Texas, I REALLY need my AC!

I'll try the jumper trick tomorrow to see if that tells me anything.
Thanks again!
Bill

[dexadel]

Thanks Crewzin for the help on jumping the switch. And slarty too for the help. That helped me figure out the problem.

Now for something funny and embarassing- it was low on r-132....

I checked the level before I took it to the mechanic that told me it was the fan, and the levels were fine. I didn't think to check it again after. Apparently he drained some of the 132, because it was low. When I jumped the switch to test it, the compressor kicked on, but it was still blowing warm. So I hooked up my guage and sure enough- not enough r-132. The compressor apparently wasn't engaging because the pressure in the system was so low that the "LOW PRESSURE cycling switch" wasn't engaging the clutch. Bypassing the switch forced it to engage.

Added a can, and it's blowing cold again. FINALLY!!! And better yet- the switch is fine too.

So the bottom line was that the radiator fan was bad, and added to that the r-132 was low after the mechanic drained it. Unless there's a leak somewhere now which is quite possible.... i'll be keeping my eye on that.

Thanks all for your help- this is a great resource for solving these issues. I hope my mistakes and problems will help others to figure theirs out as well.

-dexadel

[slartyblarfast]

That's one of those times where several different issues add up.... Been there done that.... Can be a real pain!

[BB]

What's the trick for removing the connector? Mine does not want to come off and I'd rather not break it!
Bill

[sawdust123]

Originally Posted by slartyblarfast

I've also experienced cars that the low side of the fan will work so the car doesn't overheat but the high speed doesn't work so the a/c doesn't work very well or at all at idle. Just had one last week that did that. Never did overheat but the a/c would work intermittant at idle...

Is there an easy diagnosis for this. My AC takes a while to get cold but now that I think about it, it may be because I am driving slowly for a while before I hit the freeway.

[CREWZIN]

BB,

Did you get the connection to the pressure switch off yet???

If not, just push in on the side of the clip that's facing forward and pull up at the same time. It should come off without a problem. If you use a light, you can see the two holes inside the rim of the part of the switch that's still connected to the silver canister. A bent paperclip into each hole will make the compressor come on with the air-conditioner controls set properly. If not the pressure switch is bad. If it is, replacing it will be fun, not too much space back there to work.