AC trouble
Thread Starter
Cruising
Joined: Mar 2020
Posts: 14
Likes: 1
From: Loretto, Tennessee
AC trouble
I have a few issues going on and I am not convinced they are related. First of all no blower. No air comes out of any vent at all, ever. Dead. Second, the previous owner converted the system to r134a. Clutch only ATTEMPTS to come on when pressing auto. I jumped the low pressure switch and it stays on. Good. Since its r134a i can use store bought cans. Checked pressure with clutch off, can only says red, somewhere around 80psi. Clutch on it says empty 20psi. Could be low on freon, i added a little bit, needle didnt seem to move. Even with the switch jumped, blower wont come on. Are these issue related?
Advanced
Joined: Jul 2016
Posts: 67
Likes: 12
From: Morganville NJ
The clutch won't pull in until the low side pressure is above a certain point.
Do you have a manual HVAC or Automatic (C68)?
The C68 system will do some diagnostics via the display by show DTC codes.
Using a FSM makes it easier to diagnose. Also, I have a '93 that was converted before I bought it. They did a horrible job. All the old O rings were still installed.
I basically had to take it apart, flush the lines, replace the O rings with the correct ones for the newer oil used in 134a systems. Vacuum it tight, refill. The issue I had is the previous owner rigged up a wire to the clutch from the passenger side fuse panel. Long story short, there was a blown driver IC in the PCM. This is what the repair shop said. Worked as designed after repair.
So, start with what option HVAC you have. If you have a FSM, go through the steps. Ask more questions.
Do you have a manual HVAC or Automatic (C68)?
The C68 system will do some diagnostics via the display by show DTC codes.
Using a FSM makes it easier to diagnose. Also, I have a '93 that was converted before I bought it. They did a horrible job. All the old O rings were still installed.
I basically had to take it apart, flush the lines, replace the O rings with the correct ones for the newer oil used in 134a systems. Vacuum it tight, refill. The issue I had is the previous owner rigged up a wire to the clutch from the passenger side fuse panel. Long story short, there was a blown driver IC in the PCM. This is what the repair shop said. Worked as designed after repair.
So, start with what option HVAC you have. If you have a FSM, go through the steps. Ask more questions.
