1998 LSC AC Troubles

[60ridesagain]

Guys-and gals- new here. Nothing else has worked.

1998 LSC, purchased in 2011 w/ 67,000 miles. AC was not working properly, left at shop. Multiple problems: Compressor, condenser, accumulator/dryer, control module (fan), etc...this was September in Arizona, blew cool air: next summer it would blow warm when ambient reached 110, mornings and evenings fine. Fully charged.

Now has 93,400 miles. Vacuumed/recharged system day before yesterday: blows cool air (not cold), even at 107 BUT, pressures are high: Low @ 50/High @ 325 @ idle. Water across condenser, numbers drop to 30/250, air cold.

65 YO, decent mechanic but never good with AC. Whatever it is was never fixed back in 2011 obviously. My 1995 Mark would blow you out even with the ambient above 110. Any help is appreciated in advance. Stymied?

 

[joegr]

...BUT, pressures are high: Low @ 50/High @ 325 @ idle. Water across condenser, numbers drop to 30/250, air cold...

Sounds like the problem is with the engine cooling fan.

 

[60ridesagain]

Sounds like the problem is with the engine cooling fan.

Appreciate the reply...engine temp is normal in the summer, cooler in the winter: Could the fan still be a problem?

 

[joegr]

Appreciate the reply...engine temp is normal in the summer, cooler in the winter: Could the fan still be a problem?

Does the fan come up to full speed when you are getting the 250 PSI and up pressures? Is the airflow then very good?
If not, then it's the fan, fan controller, or AC high-side pressure sensor.

The fact that it cools and the pressures go to correct when you cool the condenser with water says that it is not be adequately cooled by air. The fan would be the factor there, unless the condenser fins and/or radiator fins ate clogged with dirt/leaves/whatever. Either way, you can't be getting good airflow.

 

[60ridesagain]

Does the fan come up to full speed when you are getting the 250 PSI and up pressures? Is the airflow then very good?
If not, then it's the fan, fan controller, or AC high-side pressure sensor.

The fact that it cools and the pressures go to correct when you cool the condenser with water says that it is not be adequately cooled by air. The fan would be the factor there, unless the condenser fins and/or radiator fins ate clogged with dirt/leaves/whatever. Either way, you can't be getting good airflow.

Fan speed was high at the higher numbers, once we sprayed the condenser with water and the numbers dropped the fan speed kicked down. After the pressures began to increase the fan went to high speed again. Thanks again. I do fully agree that air flow is in someway diminished.

 

[xtriggerman]

The first thing I would check is the blend door arm behind and to the left of the glove box as pictured at the end of my how to fix article... Ultimate Blend Door repair & modification / * UPDATE * flopping loosely or firmly in place with the actuator arm, If firm, keep tracking down your issue. If the grey arm can be moved by hand, follow the directions in the link for that particular fix. It could be all or part of your problem.

 

[germansheperd]

On these cars I’d have to agree with Xtriggerman. The very first thing I’d check is the blend door actuator. Mine broke last year on my 97 LSC with 37k mi. I had cool air and no heat. It was a joy to fix! There is no rhyme or reason at the age or where the temp is set when these things break.
On a normal car I’d say condenser first then fan but these cars are their own animals.

 

[60ridesagain]

The first thing I would check is the blend door arm behind and to the left of the glove box as pictured at the end of my how to fix article... Ultimate Blend Door repair & modification / * UPDATE * flopping loosely or firmly in place with the actuator arm, If firm, keep tracking down your issue. If the grey arm can be moved by hand, follow the directions in the link for that particular fix. It could be all or part of your problem.

Thanks. It is broke, a piece had fallen out a year or so ago...I haven't done anything with it due to tearing the dash out. Didn't think it would influence the AC as it seems it has. I obviously shouldn't think so much. I really do appreciate the assistance.

 

[60ridesagain]

On these cars I’d have to agree with Xtriggerman. The very first thing I’d check is the blend door actuator. Mine broke last year on my 97 LSC with 37k mi. I had cool air and no heat. It was a joy to fix! There is no rhyme or reason at the age or where the temp is set when these things break.
On a normal car I’d say condenser first then fan but these cars are their own animals.

Thanks. "On a normal car", yes sir, these things are anything but normal! As I just shared with Xtriggerman, mine has been broke for awhile, half of it fell out already. Didn't put two and two together.

Finest automobile I've ever driven but an absolute devouring beast at times! Just too much plastic and too many discontinued parts.