93-Z34 Lumina AC ??

[34ford]

Replaced the compressor on the 93 Lumina with the 3.4 motor. Had a terrible noise and I decided it was the clutch on the ac so I replaced the whole compressor. Problem was that it was the water pump not the ac compressor. Bad on my part. Now the problem is that I did replace it with a new unit. Vacuumed it down and put in 2 cans of 134a. With the motor running the clutch will not engage. All worked well before the compressor replacement.

Any ideals what might be going on. The clutch on the compressor has a 2 wire plug so I'm not sure if what to hook up to see if the clutch will engage. (the one on the 34 coupe has only one wire and it grounds through the housing.) Can't find any blown fuses. Swapped a couple of relays around also and that didn't help. Thought about jumpering the pressure switch but it has 3 prongs on it so that's not easy to figure out either.

thanks

[wayne petty]

i went looking for the wiring diagram for that model...

usually the BCM or the PCM controls the AC clutch...  

there is usually a  Pressure SENSOR in the AC system that tells the computer exactly how much pressure there is in the system...

the closest i can get in print is a 1990 pontiac GP manual...  i don't have much on HVAC as i do mostly drivability issues..

if you still have a problem..  tuesday.. post.. an update to this thread.. i will dig the 1990 manual from the bottom of a big stack of manuals...

[tomslik]

clear codes yet?
some caddies won't let the a/c turn on until the code be gone...

[Mikej]

You might not have enough gas in it yet.

[34ford]

My neighbor who owns an ac refrigerant company helped me put the gas in and said that there is more than enough to activate the pressure switch.

I have not looked for any codes cause I just unhooked a good unit and replaced it with another good unit (i assume anyway.)  Maybe I will have to go the local parts store and have it scanned for codes.

thanks for the input so far.

[wayne petty]

its a 93...

use a jumper wire between the A and the B terminals of this connector under the dash...
count the check engine light flashes...










to clear the codes on a 93... you just have to disconnect the battery or pull the 2 or 3 ECM fuses...   there is probably just one that needs to be pulled but i don't recall which one it is right now..

[wayne petty]

did you see this post i put up about OBD1 scan tools...


http://forums.vetteweb.com/70/9096531/corvette-tech-discussion/scan-tools-that-work-w-later-c3-and-c4-corvettes-t/index.html

[34ford]

Will try getting the flash count.  Dumb question is how do I figure out the code by the flashes??  Is one long flash and 2 short ones =12  ??

Thanks for the help Wayne

[enjenjo]

one flash, pause, two flashes, pause, will be 12

[river1]

one flash, pause, two flashes, pause, will be 12

from a long ago memory, it then repeats, right?

later jim

[enjenjo]

one flash, pause, two flashes, pause, will be 12

from a long ago memory, it then repeats, right?

later jim

Yes, then it will go to the next code.

[tomslik]

one flash, pause, two flashes, pause, will be 12

from a long ago memory, it then repeats, right?

later jim

yep, it'll flash code 12 three times and then on to the "real" codes...
but i'd disconnect the battery and step on the brake pedal  to clear the codes.
trust me...

[Mikej]

Do you have power to the pressure switch? Power to the Compressor? Kiss principle

[enjenjo]

You can "force" the compressor by applying power to one terminal on the plug, and grounding the other. You don't even need the engine running to do this just to check clutch operation.

[34ford]

You can "force" the compressor by applying power to one terminal on the plug, and grounding the other. You don't even need the engine running to do this just to check clutch operation.

Hope to get to work on it again sat. Thanks for all the input. Things have been busy at work and the evenings seem to be full too.