'86 SE 2.8 4 spd. AC Compressor won't engage (Page 1/1)
FieroV6Dude
JUL 01, 09:49 PM
I've followed all of the factory service manual steps and I'm down to not getting a ground from the ECM at the Compressor Relay. I have 12 volts on the light blue to ground but when testing from light blue to the dark blue from the ECM there is nothing.
Any suggestions beside replacing the ECM and does anyone have a good ECM for an '86 2.8 4 spd around they'd like to sell?
Thanks Glenn
theogre
JUL 02, 11:18 AM
ECM uses 2 wires for AC...
1 is all other switches are Close telling ECM you want AC. This pin is an Input to ECM & Ω meter means nothing & can damage the ECM testing wrong ways.,. Then 2nd is On to Ground the clutch relay.
The ECM can ignore you & turn Off the relay when you "floor the gas" to protect the pump etc..
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
ECM uses 2 wires for AC... Ω meter means nothing & can damage the ECM testing wrong ways.,.
Then 2nd is On to Ground the clutch relay.
I only used my multi-meter in voltage mode testing at the relay between Lt. Blue and Dark Blue but saw 0 volts. I did see 12 v between Lt. blue and ground. Pulling the console today to test at the ECM and getting a good test light. Also waiting on a cable for WinALDL to verify the ECM is requesting compressor on. I had a real nice OBD 1 scan tool that mistakenly got sold in the moving sale when I moved to northern Michigan. oops.
