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AC questions - mine doesn't work and it's been hot for months (and I'm moving slowly)

Jumpering the pressure switch will divide the problem for you. No compressor = electrical problem. Compressor but no cooling = charge problem (i.e. leak). However, it is possible to have both problems.

FYI, the low side pressure switches go bad on a regular basis. The contact resistance gets too high to engage the clutch. However, they generally can still pull a relay, so you can add a relay to fix this problem. Then your maintenance is just new relays ($3?) instead of new pressure switches and the current is so low that you stop ruining the pressure switch contacts. And BTW, the pressure switches are adjustable. You want to tweak the setting a little when you switch from R-12 to R-134 and it brings the vent temps down a bit.

If you want to go much further, you will need a gauge set, but I have done jobs before with nothing more than a can tap and a single gauge (for the high side) after paying a shop $15 to vacuum the system down. With CK5 and a modest tool investment you can do this yourself for less money than one trip to the shop.
 
KansasTwister said:
ill be doing this soon. my 83 had no belt, so i am debating putting a belt on and seeing if the compressor is locked up (something you may need to try as well seeing as it was "squeeling", and then if it either needs charge or compressors bad i plan to replace all seals, new accumilator and new orifice tube. then take it to a shop have them dry it and charge it for me (buddies dads shop)
Click to expand...
Mine has a belt on it. Always has and always has spun with no squeal. Beyond that though...:confused:
Chevy305 said:
I just fixed the A/C in my S10. It never worked since I bought it, so I ran a jumper wire to apply 12v directly to the compressor clutch. It engaged and ran but never felt any temperature difference between the compressor outlet and inlet. So I charged maybe a few ounces into the system and it started working. So I shut off the engine and listened for leaks. The compressor turned out to be leaking slightly so I replaced the compressor, pulled a vacuum on the system and it held. Then I proceded to charge it full and now I have ice cold a/c.

Things to look for:
-Does the compressor clutch spin by hand (the part inside the pulley)
-When compressor is running wait to feel a temp difference between compressor ports, it may take a min or two
-Don't forget about oil in the system
Click to expand...
Okay, I'm dense. Which ports should I be feeling for a temp difference?
Oil in the system...is it in the cans of R134a or is this something completely different?
Blue85 said:
Jumpering the pressure switch will divide the problem for you. No compressor = electrical problem. Compressor but no cooling = charge problem (i.e. leak). However, it is possible to have both problems.

FYI, the low side pressure switches go bad on a regular basis. The contact resistance gets too high to engage the clutch. However, they generally can still pull a relay, so you can add a relay to fix this problem. Then your maintenance is just new relays ($3?) instead of new pressure switches and the current is so low that you stop ruining the pressure switch contacts. And BTW, the pressure switches are adjustable. You want to tweak the setting a little when you switch from R-12 to R-134 and it brings the vent temps down a bit.

If you want to go much further, you will need a gauge set, but I have done jobs before with nothing more than a can tap and a single gauge (for the high side) after paying a shop $15 to vacuum the system down. With CK5 and a modest tool investment you can do this yourself for less money than one trip to the shop.
Click to expand...
Wow uhm...uh...I'm going to blame it on the headache and come back later and reread this. I got nothing. Damn big words and throbbing eyes.:crazy:
 
Blue85 said:
Jumpering the pressure switch will divide the problem for you. No compressor = electrical problem. Compressor but no cooling = charge problem (i.e. leak). However, it is possible to have both problems.

FYI, the low side pressure switches go bad on a regular basis. The contact resistance gets too high to engage the clutch. However, they generally can still pull a relay, so you can add a relay to fix this problem. Then your maintenance is just new relays ($3?) instead of new pressure switches and the current is so low that you stop ruining the pressure switch contacts. And BTW, the pressure switches are adjustable. You want to tweak the setting a little when you switch from R-12 to R-134 and it brings the vent temps down a bit.

If you want to go much further, you will need a gauge set, but I have done jobs before with nothing more than a can tap and a single gauge (for the high side) after paying a shop $15 to vacuum the system down. With CK5 and a modest tool investment you can do this yourself for less money than one trip to the shop.
Click to expand...

How do you adjust the switch? I never knew that. Anyway, please share:D
 
AJMBLAZER said:
Okay, I'm dense. Which ports should I be feeling for a temp difference?
Oil in the system...is it in the cans of R134a or is this something completely different?
Click to expand...

The only two lines coming out of the compressor, one is the suction and one is the discharge. The suction is the bigger line coming from the evaporator which is where the cool air blowing over it comes from, the suction should be cool to around 45 degrees or so. The discharge line should be 120 degrees because thats what the compressor puts out, like an air compressor refrigerant gets hotter when compressed. The discharge line leads to the condenser which is located in front of the radiator.

For now don't worry about the oil we'll deal with once you know it the compressor even spins. When I say spin I dont mean the belt turning the pulley, I mean the inner clutch of the pulley turning. When activated the electro-magnetic clutch holds the two halves together thus turning the compressor with the pulley.
 
Am I going to need to disconnect those lines or is this one of those "touch and guess" things?
 
You can just test the lines by hand with the compressor running. It should be a very noticeable difference between them.
 
AJMBLAZER said:
Am I going to need to disconnect those lines or is this one of those "touch and guess" things?
Click to expand...

No need to, once the compressor clutch is engaged just wrap your hands around the lines and feel for a big temperature difference. 45 to 120 is very noticable. If you dont feel any difference or very little difference, then you dont have a charge or not enough of a charge in your system.
 
So I dinked with it some more tonight. How the heck is it the second week in July already?:doah:

Anyway, the compressor doesn't seem to spin. If I'm understanding this correctly the outer part shouldn't spin until the AC is turned on or the switch is jumpered?

Mine didn't with either. In fact, I really can't make it move. If it's supposed to spin by hand it doesn't. The inner part with the belt on it spins just fine.
 
k, talked to a professional today. He said i only need to change drier, go to a variable oriface tube, drain compressor oil and fill with ester oil, and new front compressor seal. He said because i have a truck, the front condenser wont change much, it will lower the heat of the system but not at the vent.
 
so, aj, did you get anything done?


With ac on, compressor clutch does not engage. when i jump the lp switch, it engages, but you can hear a rattle. she may be out of freon complettely. WIll be taking off to change oil, i have read its refilled by putting oil into the hose inlets, how much ester oil is required?
 
Does buying a compressor from Kennyw count?

Just waiting on that to get here. Probably going to just pay a guy I know to do it. Professional AC type guy/mechanic and I get the "fiance's friends' friend" discount on his work. With the way everything I've touched by myself has gone lately I'm not going to dick with this. I'll gladly pay someone a couple hundred to have it done in a day and working afterward.
 
ya dont blame ya there, im gonna do everything i can myself. Compressor should hold roughly 6-8 ounces of fluid i believe, so gonna do 8 to be on safe side (since bottles are sold in that size). Pop my compressor off, turn it upside down and rotate it to get rid of old oil, use air comp blow it out, fill it with new oil while rotating it, reinstall, new front seal, and wala!


Oh, and discovered my ac has no current freon in it for whatever reason. Took off low pressure valve and just came off easily, no pressure release, dont know if thats good or bad for my goals lol. Gonna put on a new low pressure switch while im in there.
 
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