Hi all,
I have a '93 Aero with rear ac/heat. I just got this last winter and until last week the air didn't work but the compressor did cycle in short intervals. I added one can of R12 I still had lying around and the cycles got longer and the vents felt a little cooler. This week I bought a good gauge and a friend at work gave me 2 more cans of R12 he had lying around. I put the gauge on the low side and started to add more R12. Low side was going up and down good. Before I had a half can more in, the low side quit going down and the compressor quit cycling of course. Now when the engine is hot, air temp 85, ac off, the pressure is around 110 both sides. When I turn on the ac (front only) the high side starts cycling around 150 - 200, then slowly climbs in its cycles. After a minute the cycles are starting at 300 and climbing to 350+ and I shut the ac off for fear of damage. The low side is still in range but never drops low enough to cycle the comp. The vents are still barely cool when this is happening. I get the same results when I turn both front and rear ac on except then the rear vents feel a little cooler and the fronts stay warm. Seems like something clogged but any help on where to start would be great.
thanks,
Keith