1986 A/C problem.
Thread Starter
Intermediate
Joined: Mar 2009
Posts: 35
Likes: 0
From: Newton Ks
1986 A/C problem.
A/C system is full, checked all pressure switches, have also ran a grounded jump wire to compressor and it works.
Checked the voltage to compressor.
Have 12V at both green and black wires so voltage is incorrect at the green wire.
The FSM says to then check the VOLTAGE BLOWER CONTROL MODULE CONNECTOR they are both correct.
It says if both are correct to replace the BLOWER CONTROL MODULE.
Have replaced the BCM with a use one that got from an online store and the the compressor is still doing the same thing(nothing).
I was wondering is there any way to test the BCM?
All the test from the FSM says replace the BCM.
Any help is appreciated.
Checked the voltage to compressor.
Have 12V at both green and black wires so voltage is incorrect at the green wire.
The FSM says to then check the VOLTAGE BLOWER CONTROL MODULE CONNECTOR they are both correct.
It says if both are correct to replace the BLOWER CONTROL MODULE.
Have replaced the BCM with a use one that got from an online store and the the compressor is still doing the same thing(nothing).
I was wondering is there any way to test the BCM?
All the test from the FSM says replace the BCM.
Any help is appreciated.
Pro
Joined: Oct 2006
Posts: 734
Likes: 0
From: Bryan Texas
This thread helped me figure out my bcm was bad. Mine is an 89, not sure if they are the same or not.
http://forums.corvetteforum.com/c4-t...r-problem.html
http://forums.corvetteforum.com/c4-t...r-problem.html
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Ok, If you have 12 volts at the black wire, you are doing something wrong.
you need 12 volts at the green wire, but the black wire is the ground for the compressor clutch. try putting an ohm meter on the black wire with the connector off of the compressor.
You should get zero ohms. (full meter deflection) Then switch to 50 volt scale, and then turn on the car and switch the A/C on. Now you get 12 volts on the green wire. The black will not have volts.
plug the connector back on to the compressor, and disconnect the black wire from ground. It too will read 12 volts.
ground the black wire, and the compressor clutch should click.
you need 12 volts at the green wire, but the black wire is the ground for the compressor clutch. try putting an ohm meter on the black wire with the connector off of the compressor.
You should get zero ohms. (full meter deflection) Then switch to 50 volt scale, and then turn on the car and switch the A/C on. Now you get 12 volts on the green wire. The black will not have volts.
plug the connector back on to the compressor, and disconnect the black wire from ground. It too will read 12 volts.
ground the black wire, and the compressor clutch should click.
