AC Wont come on

[Sharkstooth]

Its funny because it orked fine last night and this morning before i shut it off and now at lunch it will not work.Is there a fuse or relay that goes bad on these and if so where is the location so i can fix it because i am pretty sure it is full of freon because it blows ice cold when it worked.Any help will be much appreciated especially for my ride home at 4 pm,and down here in South Fl it gets really hot.Also,i can feel the fan by the radiator coming on and i thought that was on the same cicuit but i could be wrong.Thanks ahead of time for any help.

[wheelgarage]

Right behind the intake box, there is the main fuse/relay box.

Pull the top off and look at the underside, and chk the related fuse and relays.

[Sharkstooth]

Originally Posted by wheelgarage

Right behind the intake box, there is the main fuse/relay box.

Pull the top off and look at the underside, and chk the related fuse and relays.

Thank you,but i already checked there,I was wondering where the actual relay is.I see two relays above the radiator fan and did not know if that was one or not.I don't have a repair manual to show what each thing is for but i will get one this weekend.I brought a couple of relays home from my work so if i find a bad one then i can fix it.

[CREWZIN]

Sharkstooth,

Your the one who gave help to someone else when their air wouldn't come on. You told him about the temperature switch. The person who asked the question never came back after I told him about the other switches so we don't know what he did.

The computer, temperature switch, high pressure and cycling switches all have control over the compressor.

My bet would be the pressure or cycling switch.

My Corvette did the same thing. A/C compressor just stopped working. I shorted out the cycling switch and the compressor started working so I knew it was the a bad switch. I didn't take my own advice and bought one from Auto Zone ($14.95). It worked for about a week. Went to Chevrolet and bought a GM part ($33.00) and it's been working fine for awhile now.

If you replace any of the switches, don't be cheap (like me). Actually when the air stopped it was a weekend and the Chevy dealer was closed, that's why I went to Auto Zone.

[Sharkstooth]

Originally Posted by CREWZIN

Sharkstooth,

Your the one who gave help to someone else when their air wouldn't come on. You told him about the temperature switch. The person who asked the question never came back after I told him about the other switches so we don't know what he did.

The computer, temperature switch, high pressure and cycling switches all have control over the compressor.

My bet would be the pressure or cycling switch.

My Corvette did the same thing. A/C compressor just stopped working. I shorted out the cycling switch and the compressor started working so I knew it was the a bad switch. I didn't take my own advice and bought one from Auto Zone ($14.95). It worked for about a week. Went to Chevrolet and bought a GM part ($33.00) and it's been working fine for awhile now.

If you replace any of the switches, don't be cheap (like me). Actually when the air stopped it was a weekend and the Chevy dealer was closed, that's why I went to Auto Zone.

Thanks for the info,i am going to check everthing after dinner but i am wondering if something became coroded because they washed and detailed the engine comp.,but i will find out later.

[notmyptcruiser]

Hello all.. new to the forum... My girlfriends '05 PT (GT-conv-turbo-25k mi) has a similar issue. Freon is full, but no power at the a/c low pressure switch. All fuses are OK... Any thoughts on an initial directtion? THANKS! [/B][/B]

[CREWZIN]

Originally Posted by notmyptcruiser

Any thoughts on an initial directtion? THANKS! [/B][/B]

Look at the postings above yours. There's only a couple things in the A/C system including the computer.

[Sharkstooth]

The same symtoms are happening to this car as my last one.I had a friend check the whole system and was just a little bit low but not much.He evacuated the system and did a vacuum test and was good.Then put the freon back in and was working great and blowing ice cold.It was reading in the 40's with a temp gauge in one of the ac ducts which is excellent.When you drive down the road after 10 min,its shuts off.My last car had the same problem and it was the temp sensor in the evaporator,has anyone else ran into this type of problem with a newer car or no.I am taking it back tommorrow to have the place that i bought it from to fix it because it is still under their warrenty and there is no sense in me spending the money .This seems a little weird if it has the same problem,but who knows.If anyone has anymore input,i would be glad to hear it.

[CREWZIN]

I think the added information you just said might be the biggest clue. The A/C system shouldn't be that cold. When it gets that cold, it means the cycling switch located on the accumulator isn't working. The compressor never shuts off (cycles) and it gets so cold, the evaporator freezes up and stops any cold air from getting into the cabin. But, if your getting air into the cabin and it's warm, then forget that scenario. That's what happened to mine and it's an easy fix with a new cycling switch.

[Sharkstooth]

Originally Posted by CREWZIN

I think the added information you just said might be the biggest clue. The A/C system shouldn't be that cold. When it gets that cold, it means the cycling switch located on the accumulator isn't working. The compressor never shuts off (cycles) and it gets so cold, the evaporator freezes up and stops any cold air from getting into the cabin. But, if your getting air into the cabin and it's warm, then forget that scenario. That's what happened to mine and it's an easy fix with a new cycling switch.

It blew warm air yesterday,only because the clutch wouldnt come on and the car was really hot from sitting in the sun.Today after we got the clutch to work and check the system it blew awesome,in fact i actually had to turn it down for ten min because i was freezing in the car and when i turned it back up it would just blow cool air and i could tell the clutch wasnt kicking in.Do you have to evac. the system to put the switch in or no.Thanks for the help.