I've been troubleshooting my a/c.....put an outside air temperature sensor on it, and now it gets the outside temperature.....but it still isn't working (it had been working without the sensor). I checked the voltage on the two wires going into the compressor.....12 good volts. Does this mean it's the magnetic clutch on the compressor itself? Also, is $191 a fair price for the clutch?

 

If you haven't done so, either disconnect the battery or pull the courtesy/clock fuse and reinsert it. When reconnected, it will take about three minutes after the engine starts for anything to happen, but this resets the dash assembly and the a/c should come on. If that doesn't do it, follow the green wire to the blower control module on the evaporator housing and remove the connector. With the ignition in run, engine not running, and the a/c on, ground the green wire - a/c clutch should engage. If not, and if you have voltage on both wires to the clutch, its probably the clutch coil. If you replace the clutch, make sure to get the shim kit - it isn't included with the A/C Delco clutch. You want a .020 air gap between the pressure plate (outside hub) and the pulley. $191 is about right for the A/C Delco replacement and it includes the connector. Aftermarket, such as Factory Air (not the best quality, it comes with the shims, but you will have to wire the connector), is about $150.

 

sounds like you know what you're talking about! :)
I'll try that....I already ordered the new clutch, where could I get the shim kit from? (Autozone didn't say anything about it...obviously)

Thanks

 

If you ordered from Autozone, it's probably a Factory Air part and it will include the shim kit. Otherwise, you can get it at any Chevy Dealer - around 9 bucks for a half dozen washers!

 

well, I did what you recommended....the fuse trick didn't do anything.....so I checked the wire (grounded it).....click, the clutch engages...guess it's okay. So, I checked the voltages on the wires....all of them have twelve volts w/ the car running....is that normal? :confused: :cuss

 

keep a close eye on the pulley from the zones clutch kit. Mine and a friends (both from the zone) failed the same week . pulley bearings disappeared after a run to 140 my friends suffered the same failure without the 140 run. just an fyi

good luck
david


[Modified by hotwilzz, 9:33 PM 8/3/2002]

 

Yes, you should have voltage on both wires. Clutch coil gets ignition voltage from the a/c fuse; circuit is through the coil and back to the blower control module, which, when it gets an a/c request signal from the dash assembly completes the circuit (supplies a ground), energizing the coil. Since it worked before you replaced the outside air temp sensor, I'd think the module is good, but you might want to check it's ground which it shares with the blower motor. Disconnect the blower motor and use a DVM to check continuity on the black wire to ground. If it shows a good ground the module is probably ok. At this point, sounds like the dash assembly isn't resetting after replacement of the outside air temp sensor.
Anytime that sensor is disconnected, it goes through a reprogramming process wherein it determines the position of the air door controlling how much heat is allowed to circulate across the evaporator. A no blower (and no a/c) condition will occur for about 3 minutes. Try disconnecting and reconnecting the sensor. Then pull & reinsert the fuse again and see if it doesn't come on.

 

Ok, unplugged all that stuff.....reconnected, started the car, waited ten min.....blower comes on, but it's still blowing hot air. The black wire going to the blower does have continuity. arghhhh.

 

Well, everything seems to point to the dash assembly. Removing it's memory power by pulling the courtesy/clock fuse or disconnecting the battery should have forced it to reset and run the a/c. In order for it to send the voltage signal to ground the clutch circuit, the low pressure & high pressure cutout switches must be closed and there needs to be a completed circuit to the ECM. The low pressure switch is mounted on the Evaporator outlet. Disconnect the harness and check for continuity across it's terminals. You can also jumper the the harness with a paperclip. If the compressor runs with it jumpered, the charge is too low to close the contacts or the switch is bad. The high pressure switch is mounted on the smaller line to the Evaporator next to the fan switch. Its harness is light green and black wires. Make sure the connector is tight. If this switch reads open on your DVM, replace it. The ECM signal is at pin B8 and should have more than 6 volts with a/c requested. If both switches are closed and you have the ECM signal, the dash assembly should be sending the a/c signal to the blower module to ground the clutch circuit. Remove both connectors from the module and then with the ignition on, a/c on 60 degrees, check for voltage on the dark green/yellow wire. Should be greater than 10 volts. If you have good voltage, the module is bad. If no voltage, it's the dash assembly. A couple of other things to check would be the gages fuse which provides ignition voltage to the dash assembly and the red wire to the blower module which should have battery voltage at all times.

 

Freon leak ?????? does anything get cold under the hood ???
I don't have a clue, but just replaced my entire system in my Blazer..everything working but wouldn't get cold..compressor was leaking..
Good luck..

 

Thanks SunCr,
after running all the checks I narrowed it down to the blower motor module....off to the local 'vette parts store to get the module....thanks so much for all the help.....this forum never fails to help me :)
Everybody here rocks!
:cheers:

 

That fixed it....no longer will I cook in my black interior in the hot Georgia sun. While I was at it I wired in a switch so I can control my aux radiator fan manually. Gotta get rid of all this new under the hood heat somehow, right!

Thanks to all again. :D :D :D
:cheers: