A/C compressor wont kick on - ZR-1 Net Registry Forums

mario65 · 02-09-2012

Car still has R12. I had a shop do a quick look and they said it has plenty of freon. They sent 12 volts to the compressor and it kicked on fine. I have a flashing A/C light when I first crank it. I checked for A/C codes and there arent any. Is there a relay anywhere or something simple I should check?

thanks

tpr60 · 02-10-2012

Had a buddies A/c do the same thing, chased the wiring and problem for a whole day. End up replacing the dash a/c controller with a used one out of a 90 L98, everything worked perfect. The factory wiring chart didn't seem to match how the car was built. Hope this helps.

VetteMed · 02-10-2012

Little concerned about the "has plenty of freon" comment, as without evacuating and weighing the refrigerant, that is a conclusion that really can't be made.

Measuring high and low side pressures while the compressor is running, can give some idea of the state of charge, but is not really a way to be sure there's a full charge.

To see if a low charge is what is causing the compressor to fail to kick on, the low pressure cutoff switch terminals can be jumped. this is the switch in the low-pressure (suction) line, as it leaves the evaporator core. Unplug it, jump the terminals on the plug of the harness, and see if the compressor kicks on. If it does, it's either a bad switch or a low charge secondary to a leak.

mario65 · 02-21-2012

Quote:

Originally Posted by VetteMed

Little concerned about the "has plenty of freon" comment, as without evacuating and weighing the refrigerant, that is a conclusion that really can't be made.

Measuring high and low side pressures while the compressor is running, can give some idea of the state of charge, but is not really a way to be sure there's a full charge.

To see if a low charge is what is causing the compressor to fail to kick on, the low pressure cutoff switch terminals can be jumped. this is the switch in the low-pressure (suction) line, as it leaves the evaporator core. Unplug it, jump the terminals on the plug of the harness, and see if the compressor kicks on. If it does, it's either a bad switch or a low charge secondary to a leak.

Thanks I believe its low on freon even though the guy I took it to first said it wasn't. I am going somewhere else tomorrow. I hate taking it and leaving it. I wish I knew someone I could trust with it.

petefias · 02-27-2012

Quote:

Originally Posted by VetteMed

Little concerned about the "has plenty of freon" comment, as without evacuating and weighing the refrigerant, that is a conclusion that really can't be made.

Measuring high and low side pressures while the compressor is running, can give some idea of the state of charge, but is not really a way to be sure there's a full charge.

To see if a low charge is what is causing the compressor to fail to kick on, the low pressure cutoff switch terminals can be jumped. this is the switch in the low-pressure (suction) line, as it leaves the evaporator core. Unplug it, jump the terminals on the plug of the harness, and see if the compressor kicks on. If it does, it's either a bad switch or a low charge secondary to a leak.

Spot on. That's exactly what I had to do.

mario65 · 03-05-2012

Well the first guy I took it to was either a newb or was trying to make some money. The car had slow leaked the R12 out enough to cause the clutch to not kick on. I had a another shop check it. Filled it and problem solved

You guys were right

thanks

VetteMed · 03-05-2012

Glad to hear you got the problem identified properly!

02-09-2012	#1
mario65 Join Date: Oct 2011 Location: JAX FL Posts: 33	A/C compressor wont kick on Car still has R12. I had a shop do a quick look and they said it has plenty of freon. They sent 12 volts to the compressor and it kicked on fine. I have a flashing A/C light when I first crank it. I checked for A/C codes and there arent any. Is there a relay anywhere or something simple I should check? thanks __________________ [CENTER]1967 Firebird 400 with Nunzi 467 frame off, 04 Black CTS-V stock, [/CENTER] [CENTER]2011 Ducati Diavel Carbon, 2003 Ducati ST4S, 2000 Confederate America GT[/CENTER] [CENTER]1991 Polo Green ZR-1, my big panty girl, SGC mods, Shelby wheels, mint[/CENTER] [CENTER][IMG]http://dl.dropbox.com/u/1714619/IMG_5026.jpg[/IMG][/CENTER] [CENTER][URL="http://www.transams.net"]TRANSAMS.NET[/URL][/CENTER]

02-10-2012	#2
tpr60 Join Date: Feb 2011 Location: Salinas, Ca Posts: 160	Re: A/C compressor wont kick on Had a buddies A/c do the same thing, chased the wiring and problem for a whole day. End up replacing the dash a/c controller with a used one out of a 90 L98, everything worked perfect. The factory wiring chart didn't seem to match how the car was built. Hope this helps.

02-10-2012	#3
VetteMed Join Date: Mar 2009 Location: Orlando, FL Posts: 1,828	Re: A/C compressor wont kick on Little concerned about the "has plenty of freon" comment, as without evacuating and weighing the refrigerant, that is a conclusion that really can't be made. Measuring high and low side pressures while the compressor is running, can give some idea of the state of charge, but is not really a way to be sure there's a full charge. To see if a low charge is what is causing the compressor to fail to kick on, the low pressure cutoff switch terminals can be jumped. this is the switch in the low-pressure (suction) line, as it leaves the evaporator core. Unplug it, jump the terminals on the plug of the harness, and see if the compressor kicks on. If it does, it's either a bad switch or a low charge secondary to a leak. __________________ 2004 Z06/Z16 LeMans Commemorative Edition 1991 ZR-1 #302 White/Gray (sold) 1991 ZR-1 #1147 Red/Saddle (sold)

03-05-2012	#6
mario65 Join Date: Oct 2011 Location: JAX FL Posts: 33	Re: A/C compressor wont kick on Well the first guy I took it to was either a newb or was trying to make some money. The car had slow leaked the R12 out enough to cause the clutch to not kick on. I had a another shop check it. Filled it and problem solved You guys were right thanks __________________ [CENTER]1967 Firebird 400 with Nunzi 467 frame off, 04 Black CTS-V stock, [/CENTER] [CENTER]2011 Ducati Diavel Carbon, 2003 Ducati ST4S, 2000 Confederate America GT[/CENTER] [CENTER]1991 Polo Green ZR-1, my big panty girl, SGC mods, Shelby wheels, mint[/CENTER] [CENTER][IMG]http://dl.dropbox.com/u/1714619/IMG_5026.jpg[/IMG][/CENTER] [CENTER][URL="http://www.transams.net"]TRANSAMS.NET[/URL][/CENTER]

03-05-2012	#7
VetteMed Join Date: Mar 2009 Location: Orlando, FL Posts: 1,828	Re: A/C compressor wont kick on Glad to hear you got the problem identified properly! __________________ 2004 Z06/Z16 LeMans Commemorative Edition 1991 ZR-1 #302 White/Gray (sold) 1991 ZR-1 #1147 Red/Saddle (sold)