a/c problems

R

red83

New Member
Joined
Jun 14, 2007
cant get the compressor to kick on. i vacuumed it down. it held pressure for over 2 hrs before i started. so its all good on holding pressure. it has the electronic climate control.

i have already checked the
ecm/sol fuse
a/c fuse
replaced the a/c relay
jumped the low pressure switch on the dryer
the low pressure switch had only 1.20 volts when jumped
checked the 3-prong high pressure switch (one pin had 12.2 volts)
tried to jump the compressor straight to the battery and nothing happened.
i have a max of .02 volts at the compressor

thanks for the help in advance
 
i jumped a hot wire to the clutch and ran a seperate ground wire to the other side. it will show 12+ volts that way. since it seem its completing the circuit. does that mean the coil that engages the clutch is still good?
 
If you run +12 to where the green wire was and ground the other terminal where the black wire was on the connector, and of course don't hook up the factory connector, the compressor should engage when you start the car.

If you read +12 accross those terminals the clutch coil could be open circuit and you would still read +12.

If the clutch coil were shorted it would melt the wire or spark a lot or blow the fuse if you have one in your added wiring.

Starting at the compressor and working backwards as you are doing is a good idea.
 
salvageV6 said:
If you run +12 to where the green wire was and ground the other terminal where the black wire was on the connector, and of course don't hook up the factory connector, the compressor should engage when you start the car.

If you read +12 accross those terminals the clutch coil could be open circuit and you would still read +12.

If the clutch coil were shorted it would melt the wire or spark a lot or blow the fuse if you have one in your added wiring.

Starting at the compressor and working backwards as you are doing is a good idea.
Click to expand...

the compressor does not come on when you apply 12v.

i only read 12v on those terminal when it is straight wired. i am only getting approx 0.20 volts when everyhting is hooked up.
 
If you ran power AND ground wires to the proper terminals on the clutch and it doesn't come on when you start the car I think you have a problem there.

Obviously with no voltage on the factory wiring that would be another problem also to troubleshoot.
 
Does Caspers sell an improved digital climate module. as per the installation instructions?...I could not find it on their site.....

I know You (John) are working on a new improved one...I am down to my last one...and I know they are not available at GM...

Mark
 
Hi,
I'd like to go back to your attempt to get the comp. clutch to engage. With the clutch connector dissconnected and power to one terminal on the clutch, and a ground supplied to the other,there was no engagement, right?The compressor spins freely, correct?
What is the clutch air gap?Anything over about .040, and the field will not pull the clutch in properly.By .060, you will be SOL for hookup.I have seen a bunch of these R4 compressors have airgap problems,due to clutch and internal trouble.Try powering the clutch as you did previously, and give the disc a little nudge to help engage.The clutch disc is a press fit,needs an installation and removal tool.It might drift around.
All this said,lack of power and ground to the clutch will be another issue entirely.My '83 has climate control also, of an earlier generation.The programmer,which is in the top of the HVAC box,creats lots of problems. Good luck with your situation!
 
i replaced the a/c contol module with a new gm unit (the one on the box on the firewall) and still cant get the compressor to engage. 83ttypecooled.i will try what your suggesting.

before i replaced the module i had a new problem start here it is.

the fan no longer wants to come on at any speed. it has a good ground. no heres the funny part. it has approx. between 4 and 6 volts unplugged from the fan with the switch on auto. (keep in mind this electronic climate control)

when i plug it into the fan i lose all voltage. what the hell would cause that?

and last.....the metal coil that is on the a/c control module..at the bottom of the module.....does it need to be contacting the metal body on the module?
i noticed it has a groove it looks like it sits in in the hvac box.
 
took some voltage readings

this is with the fan on auto and temp on auto

5 prong plug on module

red- 11.74v
green/black 10.17v
brown/white 11.49v
green 10.85v
purple 5.00v


2 prong plug on module

black(ground) 0v
purple 0.01v


fan motor plugged in

black(ground) 0v
purple 0v


fan motor unplugged

black(ground) 0v
purple 4.95v

4 wire connector behind heater box. only has 3 wires going out(to module and fan). and two wires going in(from the main harness).

red 11.74v
blue 10.84v
black(ground) this is the wire that has no wire from the main harness. i did try and ground it to the battery, but it did nothing to help me.
 
When you applied 12v to one side of the clutch, and grounded the other side, did the clutch engage, or not......

You may have a weak clutch...

Had this issue years ago...sometimes would engage, and sometimes not...replaced compressor, no further problems...
 
i havent messed with the compressor no more since my blower fan quit working. i figured i needed to get the blower fan working before winter gets here. if i want to drive the car any at all this winter
 
The blower motor test is to be done as follows:

IGN switch to RUN

A/C mode to VENT

Blower switch to HI

Measure accross the purple and black.

Measure accross the purple and a good ground such as the bat. neg. terminal.

See if the blower motor works by applying voltage directly with all connectors off it from the factory system.
 
0 volts

i can unplug the ground and i can get 4+volt

i can straight wire it and it will run
 
The next test is a resisitance test KEY OFF, connectors off each end where the purple wire goes, blower motor and control module itself.

Put the meter on OHMS scale and connect one lead to the purple at the motor location and extend the wire lead with a piece of wire to the inside of the car and to the purple on the control head connector.

Should read a dead short or 0 or low ohms if the wire is good between the two points.

After that is the Blower and A/C clutch control module voltage test:

Leave the connectors connected for this test.

1. IGN switch to RUN

2. A/C mode to ECON

3. Blower Mode: HI

Measure between E red connector C1 and GROUND, should read battery or +12.

Measure between D light green and black strp. connector C1 and ground, should be greater than 10 volts.

Measure between E red connector C1 and B black connector C2, should read bat. or +12.

Measure betwen A purple connector C2 and ground, should read greater than 10 volts.
 
salvageV6 said:
The next test is a resisitance test KEY OFF, connectors off each end where the purple wire goes, blower motor and control module itself.

Put the meter on OHMS scale and connect one lead to the purple at the motor location and extend the wire lead with a piece of wire to the inside of the car and to the purple on the control head connector.

Should read a dead short or 0 or low ohms if the wire is good between the two points.

After that is the Blower and A/C clutch control module voltage test:

Leave the connectors connected for this test.

1. IGN switch to RUN

2. A/C mode to ECON

3. Blower Mode: HI

Measure between E red connector C1 and GROUND, should read battery or +12.

Measure between D light green and black strp. connector C1 and ground, should be greater than 10 volts.

Measure between E red connector C1 and B black connector C2, should read bat. or +12.

Measure betwen A purple connector C2 and ground, should read greater than 10 volts.
Click to expand...
as far as checking the ohms at the blower motor wire(purple). it can not be done w/ bothe ends of the purple wire unhooked. it is the same wire that runs from the a/c control module to the fan.
its not, but 8 inches long.if i was to disconnect both ends it would have no connection to the head unit

i can check the smaller purple wire that connects to the head unit to the 5-prong a/c control module plug.(both the smaller wires and it checks out fine).


my plug-ins are different on my head unit than what you have specified above. none of the wires are the same.maybe they are some differences?

i will owe you a steak dinner (or a few) if you ever make it down south!

edit



i did not want to delete what i said, just in case it was usefull.

i did check the wires on the a/c control module in the engine bay. that were the colors you described. i had voltage to all except the purple wire. and it is on the
5-prong cluster of wires
 
The reason you check the purple wire from the A/C control unit to the blower motor plug/connector is to make sure it's good between those two points and not cut or an "open circuit" between them.

It was a resistance check between the two points in case the purple wire was bad that feeds the blower motor out of the control board.

Wiring colors are for an 86 year car, last available with the climate control.

In your previous test of voltages the colors appear to be the same on your module?

One is C1 (5 wires) and the other is C2 (two wires).

Do the voltage tests with both plugged in as exactly laid out above it may tell us something.

Otherwise it appears the module is bad from the data so far. :frown:
 
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