Taurus Car Club of America : Ford Taurus Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
121 Posts
Discussion Starter · #1 ·
I just patched an ac line on my 97 sho and put some refrigerant in it and the compressor cycles but the air never gets cold and then the low pressure gets really high and the compressor quits cycling until i shut the car off for a while then it cycles again but does the same thing. Please help me my son and daughter don't like riding in the car with it being so hot.
 

·
Registered
Joined
·
56 Posts
Questions

What is the static pressure?
When it "is cycling":
What is the low-side pressure when clutch engages?
What is the low-side pressure when clutch disengages?
What is the high-side pressure when clutch disengages?

By the way - if your system was open, did you vacuumed it before charging?
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #3 ·
Didn't vacuum it i was trying to make sure it worked before i paid money to do anything to it. when the clutch engages on the low side it goes down to 20-25 the when it disengages it goes up to 35-40 until it the one time it gets really high and doesn't come back down. i don't have a gauge for the high pressure. not sure what static pressure is. it cycles about every 15-30 seconds i'd say.
 

·
Registered
Joined
·
56 Posts
Couple of suggestions

Static pressure is the pressure in system when A/C is off.

Well, I don't think it is a good idea to charge system without vacuuming - now you have mix of air, water vapors and refrigerant inside. Also, if system was open for a more or less long time, you have to replace accumulator/dryer.

About cycling problems - well, when pressure going up to ~45, cycle switch on accumulator/dryer has to close and (I don't exactly know how it works on 97, only on my 93) energize relay, what will close 12V circuit to compressor clutch.

If pressure is going up but clutch is not engaging, it may happen because of cycle switch failure, wiring, relay or clutch itself.

My personal bet is the cycle switch - when it stop cycling, try to tap it gently with something like screwdriver. If it will force it to close, replace it.
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #5 ·
I got it to work and blow cold but sometimes it will stop cycling and i tap the clutch on the compressor then it starts to cycle again. Do you think it could be the high pressure sensor on the low side?
 

·
Registered
Joined
·
56 Posts
High pressure sensor

First of all, it is not clear to me what "high pressure sensor on low side" means. High pressure cut-off switch, maybe (but, it is installed on discharge line, meaning high side).
Anyway, if you tap on clutch and that enforce it to engage (which could be just coincidence), then problem may be in clutch itself. To be perfectly sure you have to somehow measure voltage on clutch circuit just to be sure that it is 12V present, but clutch doesn't engage.
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #8 ·
First of all, it is not clear to me what "high pressure sensor on low side" means. High pressure cut-off switch, maybe (but, it is installed on discharge line, meaning high side).
Anyway, if you tap on clutch and that enforce it to engage (which could be just coincidence), then problem may be in clutch itself. To be perfectly sure you have to somehow measure voltage on clutch circuit just to be sure that it is 12V present, but clutch doesn't engage.
i was just guessing there was some sensor that kicked on the compressor on when the low side pressure got to high.

shoz123 i got the sho with the ac not working.
 

·
Registered
Joined
·
248 Posts
The problem is with the clutch.

Measure the air gap on the clutch with a feeler gauge. I believe the spec is 0.014 -- 0.033 in. If the gap is too large, the clutch will not engage. In addition, the clutch coil gets weaker with age, so even if the gap is within spec but on the higher side, the clutch may not engage.

If the gap is indeed too big, bring it down by remove a shim or use a thinner shim.
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #10 ·
The problem is with the clutch.

Measure the air gap on the clutch with a feeler gauge. I believe the spec is 0.014 -- 0.033 in. If the gap is too large, the clutch will not engage. In addition, the clutch coil gets weaker with age, so even if the gap is within spec but on the higher side, the clutch may not engage.

If the gap is indeed too big, bring it down by remove a shim or use a thinner shim.
It works sometimes for hours and other times only for about a half an hour. If it were the clutch then wouldn't it do it all the time?
 
1 - 11 of 11 Posts
Top