I so read everything I could in here about R-134a conversion and I decided that I was ready to do it. I bought a brand new dryer, 8oz of the correct oil, 32oz of R-134a, conversion adapters and such. My A/C hasn't ever worked since I've owned it (three years) so I figured the thing just needed a recharge and I'd be good. I made sure there was no R-12 left in the system and there wasn't, it was totally dry. I put in the new dryer, screwed in the conversion adapters and jumped the low pressure switch. I got the first can of oil ready to go and had someone start the ignition while I realeased the can into system. I all went in and I moved on to the next can of oil. While the oil was going into the system, I looked over at my compressor and I wasn't sure if it was on or not, since I've never actually heard it run. I started to put in the coolant and I was only able to get about 8oz in before the pressure equalized and no more refridgerant would go into the system. I wasn't sure if it was full, or if the compressor was on, or if it was or anything. I tried de-jumping the low pressure switch while the car was running and the engine bogged, but I didn't notice anything happen at the compressor. I jumped it again and the engine surged. What the... I tried the same thing with the high pressure switch and the same thing happened. Just for the hell of it, I got in the car to see if it was blowing cold air and it wasn't. At this point, I don't know what to do to. Is my compressor bad? Is there a sure fire way I can test it to make it fire up? If I get a new compressor, doesn't that mean I have to flush the system and loose all the R-134a I just bought? Argh!

Please respond to this thread. I need the exact same info.
By the way, sorry I am of no help here, and that I'm leaching off of your thread. But thanks though.

the compressor will only turn on if there is enough refrigerant in the system to allow for safe operation. the way to know if its on is whill it is running the engine idle will drop say 200 rpms for a few seconds and than pick up for a few and thean drop for a few and so on. chances are you didnt put enough refrigerant into the system add more. make sure your filling it with the car running and the ac set to max there is no need to jump eiter the high or low pressure switch.

also if you examine the compressor with the engin running you will notice a part of it that isnt spinning. you will also notice that there is a plug connected to this part. when it operates the plug sends 12 volts to the compressor clutch(the part that only spins when the ac is on and functioning) and this 12 volts energizes a coil which creates a magnetic field which in turn draws the clutch into the compressor pully and thus allows the compressor to operate.


also there is a good chance that your condensor has a leak as i have seen this to be the cause of the loss of r12 in 4 fbodies 3 i owned and 1 my friend owned
good luck

I tested that connector and it does get 12 volts. I actually thought that connector was the high pressure switch, but I guess not. Now, the front part of the compressor has a disk that is spring loaded forward, that I can press back a little. Also, I can turn the whole front of the compressor with my hand, but it never spins on its own. Is this the part of the compressor that's supposed to spin when it's running? Also, I tried adding more refridgerant, but it won't take any more. It just sits there with some in the can. There's a pretty good amount of pressure in the dryer as I have to press pretty hard to get the hose on.

that spring loaded disk will only spin when the 12 volts is applied to the coil. that is what operates the compressor. it is possible that the coil is burned out or that the low pressure switch is malfunctiong. if i remember correctly that is resposible for cycling the clutch. the way a recharge works is this: once the pressure reaches a sufficient ammount the low pressor switch activates the clutch enabling the compressor to operate and alowing ou to fill the system more. try jumpering the compressor with 12 volts and see if the spring loaded disk retracts. its best to not have the car running while you try this.

make sure you apply the 12 volts to the plug on the pully.
you need to apply 12 volts to one prong and ground the other to the engine or frame or even teh negative battery post.

Jumper it with 12 volts? Like, with a battery? The multimeter is showing 12 volts on the connector when the car is running, when I plug that into the compressor, I get nothing. That seems to prove right there that the coil is not working. Any way to fix this without discharging the system?

yes you get a pully puller from a parts store and get a replacement pully. best bet is to get the pully from a yard as dealers charge a lot of money for them. i dont really know how to pull a compressor pully as i havent done one before but i assume it can be done.

and i didnt really read your psot fully sorry.

Replace the pulley to fix the coil?

i heard from a mechanic about a year ago that gm has that safety switch if there is little or no pressure in the system the compressor wont run at all. he said the way around that was jumping the coil with power and tricking the compressor into thinking there is enough and allowing it to cylcle and fill the system. but if the coil doesnt retract then i guess your comp might be bad...junkyard time.

yeah i believe its built into the pully.

i could be wrongf but thats what i remember from ac class.

if im wrong someone correct me so i dont give the wrong info.
----------
ive heard that too.

but the compressor might still be good it could just be the coil assembly. no need to open the system if you can just replace the pully.

yeah very true, especially since he put all that work into already...

try calling an auto parts store to see if they just sell it or not, that wil get your answer. although i dont have the slightest clue on how it would come apart

ive traken them apart before.
IIRC there is a triangular tool ath fits into 3 prongs on the spring and allows it to be removed. and after thats off you should be able to remove the pully.

hold on ill go find my heating and ac book and look it up ill post back in a few.

I double checked that connector. There's something werid about it. It gets 12v, but if I wiggle it a little it looses its charge. Same thing if I plug it into the compressor, if I wiggle it a little the engine will surge, but nothing I do will get the clutch to engage.

that engine surge could be the clutch engaging. carefully watch the clutch while it surges it could be so quick you dont notice it moving.

if your getting volts where theres suppose to be volts and the compressor dont run, try checking the diode on the connector where it plugs into the clutch. my diode was bad on my iroc and when i replaced it, the system worked. just something that can be overlooked

I wanted to try and apply 12v to it while it's off, just to make sure. How do I do this? Do you get it from the battery and how?

if you want you could try that.
ive heard a 9 volt battery can be used to jump the clutch.

remember that the volatage you supply to the clutch has to be able to retun to its source.

Ok, I'll try that.

in case it doesnt engage the way to remove the pully is as follows.

get that triangular tool tat plugs into the spring.
rempve the clutch spring.

there is a nap ring under neath that that hold the pully on.
remove that.

that get a pully puller it should be a circular one and pull the pully off.

than you need a installer tool to put it back on get one and than reverse the removal procedure.
this will probably be a little tricky since its not on a bench but its not to hard.

Nope, 9v doesn't do anything.

Yeesh, look like I need to get a bunch of tools. Can I get all that at Pep Boys?

Maybe I should just start over with a new compressor...

do you have a 12 volt or more drill battery. a little 9 volt battery might not have enough amps to to magnatize the clutch and engage the clutch.

if the 9 volt diudnt do anythiing tray jumpering from a booster pack if you have one or from some source that you know has 12 volts if you can get a good connection you can use the battery. i havent personally verified if the 9 volt will do anything its just something i heard. if your gonna use a side post battery youll need to get behind the boots to get a good connection.

but yes any auto parts store should be able to supply you with these tools although i havent looked for them myself.
i wish i had a scanner so i could post the pic from my book but i dont.

you may also need to purchase a new coil.

one other test i just thought of is: if you have a multimeter set it to the ohms scale and connect the leads to the plug on the compressor clutch and see if you get a value if you get an out of limit than its bad. some multimeters just show a one on the left side of the digital readout to signify infinite resistance if you get either of those the coil is open and thus bad.

Did what you said, the coil IS open, it's bad.

Turd on a biscuit.

Now, is the coil built into the pulley for sure? I sure would like to be able to fix this without opening the system.

no i checked myh book. you can keep the pully
the coil is under the pully though so youll ahve to remove the pull to get to the coil.

Ok, now I know what I need to do. Hope this doesn't set me back too far. I'll get back here and update when I make some progress.

cool good luck

let me know how it goes you can just pm me if you want

OK, here's the deal...

The system will not let the compressor engage if there is not enough pressure in it, you know that already. You are not able to add anymore freon so you wonder if it's full already... it's not.

Here's what you need to do: Jumper out the low pressure sensor, start the engine, and then turn ON the AC. The compressor will engage the clutch and pump down the freon pressure, then you can add more freon. The way to jumper out the low pressure sensor is with a paper clip. Just unplug the connector from the switch on the big aluminum can on the passenger side (is that the dryer?). And plug the paper clip into the connector. This will bypass the low pressure switch. After you add some more freon you may actually hear the low pressure switch click. At this point you can toss the paper clip and plug the connector back on to the can.

Thank you for your reply, but I've already been down that road. All the paperclips in the world won't get the compressor to engage. Thanks to Green89, I've confirmed that the compressor clutch coil is dead by testing the resistance across the two post connectors on the compressor. After a little running around, I've found out that:

A new coil on order starts at $90 and goes up

A pulley puller/installer kit costs $50

The triangular tool to release the spring isn't available to me locally, I'd have to drive to Harbor Freight which is about 70 miles north of me

It'll be a pain in the *** to do.

I'll still have an old orfice tube.


So, I'm just going to have to come to terms that I wasted about $60 on R-134 and oil today. I'll order a rebuilt compressor off eBay or something, and a new orfice tube to boot. I gues that's what I get for not checking my hardware before I charge. Thanks very much for everyone's help, I hope this thread helps other people with a similar problem in the future.

dont get a rebuilt compressor ive heard they are very unreliable i would go for a brand new one. it may cost more but itll save you heartache in the future if that rebuilt one goes bad and you have to open your system up again in the future. also look for a compressor with the terminal that uses the stock plug with the diod in it,. on my car i have a compressor that has the newer styl coil on it and i had to cut and splice in the right connector. .not that my system works ro anything. id fix it if i didnt have t-tops though.

I've seen Camaros in junkyards with almost brand spanking new parts in them. They were just recently repaired and then they got totaled. I'll go look, maybe I'll get lucky. The junkyard I go to will exchange your part if it goes bad within a year.

Howdy, there, everyone. Luitenant Idiot of the Retard Patrol reporting in.



So my poor butt goes down to the junk yard today, and I'm scouting for a decent looking compressor. I find one that looks promising. There's even still pressure in the system! Good! So, I get started in taking this bad boy out when I notice there are TWO count em' TWO connectors connected to the compressor. This baffles me because there is only one on my compressor. I look in the back of the compressor and I see the connector that I'm familiar with - a round, circular connector that has two little "pins" in it. Pins, not slots. Then, this other connector is FLAT and connects right behind the pulley. I stare at this thing for a few minutes and start wakling back to my car. I locate these two flat prongs on my compressor -- but there's nothing connected to it... I start rummaging though my engine comparment and I come across a cable that is taped up at the end. I untape it... and lo and behold, I've found my compressor power cable. I was like "OH MY GAWD." I sounded like Joey Styles. It hit me that this circluar cable that I had been fiddling with WAS the high pressure sensor switch.


Ok, so now I have a completely new problem. This connector -- which I know connects here to these two prongs on the compressor -- gets no voltage. Ever. I tried jumpering the low pressure switch again, but no voltage. Ok, I figure I'll deal with that later. I tried the resistance test against these two prongs and got 0 resistance. Good. So my compressor should be okay, then. I just have to figure out why I'm not getting any voltage to this connector. I jumpered 12v to the compressor while it was running to see if it would engage. I think it did. Every time I touched the 12v to the prongs, the engine would surge and I heard a very faint clicking sound somewhere. However, the center of the compressor wasn't spinning, so I'm not sure. It successfully blew my AC fuse under the dash doing this, so I have to get a new fuse to get it to blow again.

I need to confirm 12v to the compressor and see if that makes it start pumping refrigerant.

More to come....

There were some huge gashes in the cable. I patched them up. I also jumpered the low and high voltage switches and the compressor finally kicked in. I only let it run for like 2 seconds, then I killed it. I was so happly. I went over to my dryer to check it. I pressed on the low end valve... barely anything, like 2 psi.

Did my compressor suck the pressure out of dryer and into the system or is there a massive leak in my system and all the refrigerant is gone? I would go back and let the compressor run to see if it gets cold, but I don't know if it sucked the oil in or if it all leaked out. Should I go buy more refrigerant and start letting the compressor suck it in this time, or should I run it to see if the there's anything in the system?

I bought another 4oz charge of oil and another 12oz of refrigerant. I plugged the low and high pressure switches back in where they're supposed to be. I charged the oil and the compressor kicked in! It cycled in 4 second intervals. I quickly charged the 12oz can and the compressor started staying on longer this time.

I went for a drive and the air coming out of the vents was... not different a bit. It wasn't getting cold! I drove around and when I went back to park, the compressor was disengaged and didn't come back on. I checked the pressure in the dryer, about 20psi, but there should be more than that...

I figure it has to be leaking...

If I put 18oz of refrigerant into the system, would it get cold at all? Or does it only get cold after the whole 40oz is in?

it usually starts getting cold after about 20 and gets fully cold around 40 i believe.

I went out to test it again. Now the compressor is cycling again! Huh?


If it's still cycling in the morning, I'm going to buy another 20oz and fill it up.

Ok, so I got up this morning and checked it... still cycling... good.


So, I went down to Pep Boys and gave them another 25 bucks for another 20oz and I charged it right there in the parking lot.

It's... cool... Cold? Sorta.

Like on a scale of 1-10 1 being room temperature and 10 being ice, I'd say it's at a 4.5 right now. Half as cold as I want it to be...

I bought a cheap pencil pressure gague that gave me 40psi at the low pressure side. I figured it was full...

I'll try it when it gets hot and see if it cools me down. If it does, then it's doing its job.

the compressor is supposed to cycle thats how it works.

Problem: Solved. My car is now colder than Santa's dillywhacker.


So, here's how I spent my day...

I'm out there, wondering why this darn thing won't get cold. I thought it was overcharged, so I started letting refrigerant out a little at a time, to see if it would get colder. No good. Finally I decided that whatever my problem was, it was inside the freaking system and I had to fix it. I let all the refrigerant out and started taking the whole system apart. I disconnected all the hoses I could and then pulled the condenser out. It looked in fair condition. I finally found my orfice tube (I didn't really know where it was) and it was an absolute disaster. 100% plugged with gunk, absolutely nothing was gonna move though that. No freaking wonder. Thankfully, there were no metal shavings in the gunk, as I examined it closely. I'm gonna hope that means my compressor is ok.

Anyways, I decide to get down and dirty. I go down and grab a set of o-rings, o ring lube, ac system flush, 32oz of refrigerant (I THINK there should be enough PAG oil left in the dryer and compressor, since those are the only things I didn't flush). I flushed all the hoses, the condenser and the evaperator. Put all-new o-ring and lube. Charged up the system to 32oz and the compressor worked just the way it should - started in the off position, started cycling as I added refrigerant, and stayed on continiously after the 3rd can. I also made sure to adjust the low pressure switch to take off about 5psi. Got in, drove around the corner... oh, yes, this is what I've been working for...


Now I have a new, kinda unrelated problem wich I will look into tomorrow. The blower is pretty weak. It's barely making it to my face - it's just a really cold kind of breeze, not the BLAST of ice that I want. Also, when I get on the freeway and really get the RPMs up, the blower goes down to almost nothing when the throttle is down. When I let off, it comes right back. At first I thought it was a weak vacuum, but it doesn't blow out the dash defrost vent while the throttle is down, so it has to be the blower.


I'll do some reading.


Thanks everyone for your help, it definately did help me along.

Jetster, thanks for sharing your experience. I'm literally just about to start working on my a/c system, and the info that you have given will really help if I run into problems. Thanks again man.

Do you mind sharing what kind of vent temperature you are getting?

I haven't taken a reading, but I will soon. Having a few problems here and there with the high pressure switch... you jiggle it and make the compressor turn on and off, so it turns on and off while I'm driving down the road... will anything really bad happen if I just permanently jumper that thing?

Hello All - Some good stuff here to get me started too. Hate that you are the Guinna Pig.. Anyway - Curious about a couple of things - 1 - Did you have to pull a vaccum on the system in order to charge? 2) Flushing - What did you and what is the method? I found flush at the local AZ store, but no specific instructions on the "how" 3) For what you have done so far, have it required any special tools? 4) Any idea what style or model compressor that you have? Appreciarte the help!

I have a quick question ... I converted my system last year, and this past week my compressor began to kick on and off, and now it doesnt want to come on at all. As I guessed, the coolant had leaked out. How do I go about finding this leak and patching it? The temperatures are running in the triple digits here in Cali so I need to get it fixed a.s.a.p.

There is a leak detecting kit you can get at autozone for r134a systems. Runs between $40 to $50. Uses a UV dye that appears at the leak site. There is also leak stop for that system. It seals leaks at the o-rings. More serious leaks must be repaired by other means.

Am I the only one who cannot find a mention of evacuating the system? Perhaps I missed it, as it is past 1A.M., and I am tired. R-134A is crap, even when done right, and this seems all wrong. Do you realize that the flushing left tons of moisture? Saturated the dryer, hoses, etc.? It is over 90 degrees here. With the air on 'normal', the cooling is mediocre at best. On ''recirculate', I have a vent temp of 55 degrees, which is impossible to achieve on a retrofit system. I flushed, evacuated, changed dryer, evacuated again, then added Envirosafe, and a variable orifice valve. I installed Ester Oil, as it is the ONLY oil compatible with all freon types. PAG only works with R-134A. That was last year. This year, I have R-12 installed. I have a leak [compressor front seal], so imagine how much cold air I have lost in the past month.

Time to search for more R-12. It is out there, and not always for absurd prices. The R-12 fairy may bless you with small cans or a 20 lb. cylinder. But you will never find any if you don't look.

Seth

If I'm not mistaken, you need to be certified to purchase R-12. It's not hard to find, just hard to buy. I've heard that in numerous places, but I don't kow how accurate it is. I'm sick of all the bull****, I'm not changing to r134a, and i'm not going crazy trying to get r-12. I just came across a local spot that sells freeze12 and although i've heard good and bad, i'm dropping it in on top of my r-12. The system is practically empty anyway. First, of course, i'm sending the dye through to see if there is a major leak, or if it's only a seal. I'll let you know how it turns out after it has been in a while.

When was the last time you needed a license from the EPA to buy R-12 at a electronics swap meet ?

I pay $10-$15/tin. Last time, the seller threw in a Robbins manifold set.
You have to be in the right place at the right time.

Do any of us follow the law to the letter, all the time?
As long as we follow our conscience, and don't harm others, no one has the rite to ask more of us.

Seth

I agree with you, but unfortunately, the government does have the right to ask more of us, and it does. I was referring to purchasing r-12 at a business, but yeah, you can certainly find someone on the side who will sell it to you. I would just hope that it is used responsibly buy the purchaser being that if it is released into the environment, it contributes greatly to the depletion of the ozone layer. Not to mention that when old r-12 is contained, it is typically recycled into a usable product since it is no longer legal to manufacture.

Just a note on the topic, I took my car to a friends shop and had him convert my AC system over to R134. My vent temperature was 42 degrees.

*deleted*

dont know how this post ended up here!