AC blows cold sometimes and Hot sometimes

Hey there. When you say that the compressor cycles on and then off, does it cycle back on? Most AC compressors have a clutch and they are designed to cycle on, off, on, off, etc. Also, you say you're trying to charge the freon but do you know how much freon is actually in the system already? Best way to recharge the ac system is to perform an evacuation of all the freon using an AC machine and then performing a vacuum on the system. Monitor the gauges to check if you start to lose your vacuum which would indicate you have a leak somewhere. If the vacuum remains the same, then you recharge the system with the appropriate amount thats located on the AC placard somewhere in your engine bay.

Yes the compressor cycles on/off then on/off repeatedly. I was not sure if that was normal or not. Not sure how much Freon is in system. Gauge on Freon kit said that it was either over charged or mechanical failure.

Just to add to this one that is not a cycling compressor most GM cars are not.The gauge cannot tell you how much charge is in the system.That is why it is best to charge a empty system so you know you have the correct amount of charge. Or what the professionals use a AC machine so they can evacuate and weigh what comes out. So they no how much charge was in the system to know if it was fully charged over charged under charged etc. Also reasons for compressor cycling too high of pressure built so compressor is shut off as well as too little of pressure can shut off as well. Also not enough air being pulled through the radiator and AC condenser do to sand debris fan not working etc.

Thanks saturntech9 for clarifying if his compressor was a cycling compressor or not. All cars I have worked on so far have a clutch. Everything else is spot on as well. Thanks for reassuring.

They all have a clutch or a bypass valve they use instead of a clutch to bypass the pressure to do the same thing a clutch does.You are welcome anytime we are here to work as a team.

Thanks everybody. Still confused, lol. Have a buddy who is more mechanical than me so we are going work on it this afternoon. I will let you know how it goes.

Alright, keep us posted.

Did not have a chance to work on it today going to work on it tomorrow morning. Seems as though the AC blows cold in drive but hot in idle?

So while driving down the road it blows cold, but when you stop moving it blows. Hot?

Yes, I noticed that today.

So is your radiator fan/condenser fan turning on with the AC?

Something definitely turns on when I turn on AC, but then it sounds like it is cycling on and off. I thought it was the compressor. But you explained it does not do that on my model. It sounds like it comes from middle of engine but I did not see anything moving. Granted I did this on my fifteen minute break by myself so I am sure I missed something. So should I check to see if fan is on first thing tomorrow?

Thanks for all your help again.

Yes see if the radiator fan/condenser fan turns on with the AC? Does your radiator fan turn on when the car warms up?

I believe so because otherwise it would over heat correct?

I have seen strange things with radiator fans not working and people only complaining about the AC only working when driving.

Point taken. I will look tomorrow and let you know.

Keep me posted.

Okay so started car and let run. Fan never turned on. Started AC. Clutch engaged fan still did not turn on. The on off noise I heard was the clutch engaging and turning off which it started to after five minutes of idle. Temperature went up two lines from normal, but did not seem to get any hotter. Thoughts?

Sounds like the radiator fan is not working properly. With the AC on at idle try smacking the fan motor see if the fan starts spinning?

If it does not then see if there is battery voltage across the two terminals to the radiator fan motor?

Okay, will give it a smack and see what is up. I do not think my bud has a multi-meter here.

Fan motor did not turn on. No multi-meter. Found new one at AutoZone. $26.00.

They rent multi meter at auto zone unless you want to buy one.

I meant new fan motor for $26.00 lol.

We do not know if we have battery voltage to the fan so a motor would be a guess. it is up to you if you want to plug a new motor in and see if the motor comes on.

I will check voltage first.

Sounds good.

Didn't have opportunity to check voltage yet. On commute to work today engine temp increasing getting hotter. Here's what it got to by my arrival. See pic. Fan motor/thermostat??

I can't blow up the picture is the car running really hot?

Almost 200 degrees warning light came on.

200 degrees isn't hot for that car I wonder which warning light came on?