1993 Mercury Grand Marquee w/ 302 ci engine.

A/C system has a small leak near the condenser. Refilled with 134a kit from wal-mart. Now compressor will come on and stay on. High side gauge reads correct. Low side not tested. No cold air comes out. High side lines does not get cold.

What do ya'll think?

6/25/2006 10:50:32 PM

clogged

6/25/2006 10:52:04 PM

remedy?

6/25/2006 10:52:25 PM

You ain't around here anymore, are ye?

You really need to see what both high and low sides read.

BTW, the high side line won't get cold. The low side line will, though. For an average day around 85 degrees or so, the low side should read around 20 psi with the engine at a fast idle (or around 1500 to 2000 rpm). The high side should range between 175 and 225 or thereabouts.

You've either put too much in there or not enough.

Where is yer leak?

6/25/2006 11:13:58 PM

The leak is super small at the bottom of the condensor, not a real problem. I must have got teh high/low sides backwards ^^^above. The low side did test out near 20 or slighty higher I beleive.

I don't think its the amount of 134a, i'm leaning more toward the clogged idea.

6/26/2006 10:56:00 AM

the car came with 134 being it's a 93?

6/26/2006 10:57:03 AM

if you got around 20psi then the evap should be cold. You may not be getting good air flow across it.

6/26/2006 11:36:34 AM

beatsunc - The evaporator is not cold.

6/26/2006 11:48:57 PM

The only thing I can think of is insufficient charge.

If there is truly a blockage in the system, then high side pressures should climb rapidly, and there should be almost a total vacuum on the low pressure side.

The damn thing is a clutch cycling orifice tube system (CCOT), so what I'm wondering is this: is there enough refrigerant in the system for phase change to occur on the high side?

One phenomenon I've noticed is that it seems that pressures will build quickly, and then dip somewhat and build again during the charging process...I'm thinking it might have something to do with reaching the point that the refrigerant actually condenses to a liquid on the high pressure side.

In truth, Matt, it's pretty damn hard to tell what's REALLY going on without having a set of gauges hooked up to it. But you ain't in the area no more, bitch.

6/27/2006 12:15:16 AM

stupid question but, did you fill it on the high side and rely on the cheap gauge that came in the kit?

if so then there lies your problem it needs to be filled on the cold side with the ac running if not than something doesnt make sense, if the compressor doesn't cycle, then it can't be clogged or low, and if it doesnt get cold, then the compressor would cycle, so it really makes no sense at all, unless the compressor is shot and it isn't pumping at all

6/27/2006 5:21:22 AM

Quote :

"the car came with 134 being it's a 93?"

6/27/2006 9:20:25 PM

^ i was wondering that too

6/27/2006 9:58:29 PM

I hope that you have done a retrofit or you are going to have a lot more leaks.

6/27/2006 10:04:18 PM

6/27/2006 10:26:33 PM

the car was filled on the low side line. The line that goes from the compressor to the evaporator. The pressure did rise and fall when filling but finally leveled out. The Compressor runs all the time when the a/c button is on in the cabin. I think the high side line is getting really hot while the low side line stays at a normal engine compartment temp. The low side never gets cold. I'll try to get some gauges hooked up as soon as possible. Anybody thought of a clog in the orfice tube?

6/28/2006 10:11:16 PM

You know damn well what the problem is.

6/28/2006 10:39:41 PM

If the high side is getting REALLY hot, then yes, it sounds like a blockage of sorts.

6/28/2006 11:36:20 PM

still should cycle, unless the compressor is worn out if there is a blockage

[Edited on June 29, 2006 at 7:38 AM. Reason : or if your high limit switch aint workin]

6/29/2006 7:37:44 AM

Quote :

"You know damn well what the problem is."

Quote :

"the car came with 134 being it's a 93?"

??????????????????

6/29/2006 9:34:21 PM

R12/R134a it doesn't matter, the R12 been evacuated. I'm running 134a refrigerent and oil stop asking me what it was orginally equipped with.

6/29/2006 11:01:40 PM

When I converted my old 626 from r12 to r134a I didn't replace any hoses, or seals other than the one that leaked, or the filter/dryer. I drained the old oil out of the compressor, replaced the front seal, filled with new oil, changed the schreader (sp) valves out, filled with a little 134a, then just vented some "air" off, and finally just put a can or 2 in the system. It ran fine, cold as shit for a couple years and it needed about 1/2 can. My dad drove the car for several more years so we probably had the car for 7 years and it needed topping off 1 or 2 more times.

I was 16 or 17 when I did this and would do it the correct way now, but nothing really seems that critical. I t wasn't efficient but it sure was cold air from a system that a mechanic told me would take $800 to fix. Morale of the story, I'm an idiot but my A/C sure was cold.

6/30/2006 6:41:49 AM