Air Conditioning works great after restarting engine!

[alia176]

Has anyone experienced this issue with their A/C? My A/C will work great and does a good job at cooling down the interior. However, the compressor will stop turning and the air will slowly warm up to ambient. I'll throw her into Neutral, turn off the engine, then turn back on and the A/C works like normal again. It's behaving like a Windows machine that constantly needs to be rebooted I do this at hwy speeds as needed. On hotter days, I need to do this more frequently.

This is not an issue with the freon overfilling or underfilling, I don't think. But, why does it do this more frequently on hotter days? Restarting the engine seems to reboot the system. I am using a second A/C Auto Amplified control unit (with the buttons and display) just to see if it improves to no avail.

Simply turning the A/C from Auto to Off then back to Auto does nothing. In fact, the air simply stops flowing when I do that. Only restarting the engine causes the A/C to work like normal again.

Two fault codes that I've gotten consistently are 14 & 15.
14 - evap sensor
15 - refrigerant sensor

When I had the evap out of the car, I checked these two sensors per FSM and they checked out. Then I checked for continuity from the sensors all the way to the Auto Amplifier termination (b3 & b4). Everything was solid and the connections were good. When the sensors were plugged into the circuit, I saw the values change at the Auto Amp terminal strip (b3 & b4). This makes sense since the system runs fine intermittently.

I wish I had a select monitor to see inside this thing!


Thanks for any help.

[trophy956]

did you look to see if the compressor is still engaged ? try swapping the A/C Relay ?

[alia176]

Good idea, I'll check out the hi/low pressure switch, and the run command to the a/c clutch coil relay. I printed out the FSM pages and will do some Dx this week.

Thanks again.