1988 Grand Marquis AC Problem

MODETTE

MEMBER
1988 ALL OTHER MAKES ALL OTHER MODELS

The AC system in this car was changed over years ago. Last summer (2006) the system worked great, it blew nice really cool air. During the winter here in Michigan I did not use the car as much and when I did I had the heat on. Come this past spring (2007) the AC was not working. No cold air blew.

Figuring the system just needed a recharging I went up to the auto store and bought some R-134a (which has the oil in it). This was about a month ago on one of those nice rare warm days we got here in Michigan. I followed the directions of having the car on, with the system set on High AC and the reading was low. It seemed hard to fill the unit but after a bit I got in the correct amount. Still only warm air blew. I shut off and restarted the car. Still nothing.

I then noticed the compressor was not kicking on. So I put more R-134a intot he system and then the compressor kicked on, but would go down drastically and then cut off again. At this point the reading was at the "Yellow" part of the gauge.

So I left it for 1-2 months and now it is warm out in the 80's. I decided to take another look today. I put the bottle with the gauge on the system (Low side) and it still said the stuff I had put in there before was in there. So I decided to let all the stuff I ahd put in there out and start over. I followed the directions ont he bottle of the R134a to the letter. This time the stuff flowed in fast and easy. I got it up in the blue and went to check the air, and it is still warm. And the Compressor is still not coming on, unless I overfill the unit but then the pressure drops kicking the unit off and once it raises again the compressor comes back on. At this point I have no clue.

Do I need to vacuum the system out? I also unplugged and replugged in the connection at the top of the compressor unit and it seems connected and still nothing.

Thank you for your help

2 Replies

MODETTE

MEMBER
3 POSTS

Thanx I will try this. The can size I have is 18oz whith plenty in the can. Yeah I was starting from ZERO for sure because I pressed the plunger in on the Low and High side untill nothing more came out.

I was just following the can directions and it was in the BLUE but I figured how can this be for EVERY car made.

Also I can get the stuff without Oil, I just happened to buy that one. I will go to Walmarts and pick some stuff up without the oila nd add it till the compressor stays on. I'll post back if this works or not :-)