AC problem
Thread Starter
5th Gear
Joined: Jul 2009
Posts: 5
Likes: 0
AC problem
93 Vette, 134 convert (sticker says so) Compressor clutch does not engage.
All Fuses pulled and checked.
Pressure guage on can says 50 psi.
no voltage at the compresor connector
I checked the low switch looks ok 12v and jumpered it nothing
High switch has 3 prongs not sure how to check it
I pulled the clutch relay, coil is 90 ohms, 12v is available on both the coil and the switch.
Whats next?
All Fuses pulled and checked.
Pressure guage on can says 50 psi.
no voltage at the compresor connector
I checked the low switch looks ok 12v and jumpered it nothing
High switch has 3 prongs not sure how to check it
I pulled the clutch relay, coil is 90 ohms, 12v is available on both the coil and the switch.
Whats next?
Heel & Toe
Joined: May 2007
Posts: 22
Likes: 0
My ac was giving me trouble when I first got the car and it was throwing the breakers on the system. I have the c68 system and the manual said to reset them by pulling the ac fuse and reinstalling. You acheive the same by disconnecting the batt. If you have the same setup the leds on the as controls will flash for one minute after you start the car when there is a problem. I ended up with a bad orfic tube later on and it is now change to 134.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Doesn't sound like the PCM is driving the relay or the PCM isn't getting an a/c request. Ground the PCM side and see what happens. Check PCM with a scanner to verify the a/c request along with the Pressure Sensor (high side) signal which should be around .8 volts or 80 psi on most days (it's not a switch - it's a thermistor with a 5 volt PCM reference and the return is proportional to pressure - approx 1 volt per 100 psi).
