Need Help, A/C system issues

[marcyprojects]

Morning all. In need of some wisdom on this as the Florida heat has been my enemy. So I recently started debugging my a/c, which has never worked since I got the car. I have a little experience with this but im still stumped here. I noticed first of all that the system had been converted to R134 (I have a 93 which is original R12), and seems to have an R134 style compressor. Next I see that the fitting on the low side was rusted, kinda bad looking, so I replaced it. Checked the freon which was very low, added 2 cans, levels check good on my gauge. Now for the main issue, it doesnt seem that the a/c clutch wants to engage correctly. I have tried swapping relays, I tried to jump the pins at the a/c relay to force it on, still nothing. The only thing that works is when I run direct power from the ignition/battery to one of the pins on the relay. I think its pin #1 or #2 but dont quote me. I actually ran it like this for a few days and everything worked beautiful but I think running it this way drained my battery as I had to jump start the car after a couple days of not driving it. My guess is that leaving the a/c clutch constantly engaged is the cause. I have read that there is a switch or several switches that could be bad, or the control unit itself could be bad but I think thats unlikely. Anyone with any experience on this? ITS HOTT DOWN HERE!!

[rabsusa]

Morning all. In need of some wisdom on this as the Florida heat has been my enemy. So I recently started debugging my a/c, which has never worked since I got the car. I have a little experience with this but im still stumped here. I noticed first of all that the system had been converted to R134 (I have a 93 which is original R12), and seems to have an R134 style compressor. Next I see that the fitting on the low side was rusted, kinda bad looking, so I replaced it. Checked the freon which was very low, added 2 cans, levels check good on my gauge. Now for the main issue, it doesnt seem that the a/c clutch wants to engage correctly. I have tried swapping relays, I tried to jump the pins at the a/c relay to force it on, still nothing. The only thing that works is when I run direct power from the ignition/battery to one of the pins on the relay. I think its pin #1 or #2 but dont quote me. I actually ran it like this for a few days and everything worked beautiful but I think running it this way drained my battery as I had to jump start the car after a couple days of not driving it. My guess is that leaving the a/c clutch constantly engaged is the cause. I have read that there is a switch or several switches that could be bad, or the control unit itself could be bad but I think thats unlikely. Anyone with any experience on this? ITS HOTT DOWN HERE!!

greetings,

when you say "filled with 2 cans levels check good on my gauge" - what exactly do you mean? ie Did you evacuate & fill? I just serviced mine last month in prepn for the long hot summer; when i say serviced i mean pulled vacuum on system for 15 mins to pull out all comtaminates, switch off n wait 5 mins for leak down testing (mine moved 1 bar - gauge fluctuation) then i refilled with 134a. Too much or too less gas pressure will cause compressor to cycle on and off - thats the built in safety of the system. In my case i overfilled slightly (q45 AC in fl has never been cold enough for me even when next to new - don't kill or come at me with yr NEG comments again bcc) then let out excess pressure until compressor kicked in and stays running.
If you simply added via lill cans in your local auto store parking lot, IMHO you just wasted 40 bucks

R

[marcyprojects]

Yea I can definately agree with the waste of cash on the refill. The biggest problem was that the autozone gauges didnt give a consistent reading. im almost postive at this point that its overfilled or needs vaccum to be pulled. I was just hoping that there was another alternative to paying an AC man to get it going. I ve always done all my own work, I get kinda funny about people taking my cars in.lol. How much did it cost when u serviced yours?

[rabsusa]

well apart from materials - nothing,,,, i m an AC guy too - towing company etc etc of my many biz'es
- all those top-ups in the stores are a COMPLETE waste of time n $$ - the efficiency of your system is a function of the amount of contaminants in the system, each time the gas expands and contracts overtime it absorbs moisture etc and loses its capacity to absorb heat. Add to that the moisture falling out under pressure and air, we have a system pressure made up of freon plus 'junk'. Its all the other junk in the system displacing your gas pressures that causing issue - think of it like your brake fluid grabbing moisture from the air - this can cause low and high pressure in the system - erratic movement of gauge readings. You need vacuum pump (mine yellow jacket - rolex of pumps), a gauge set and a tank of freon from your local sams club and your set - oh don't forget your safety glasses
then you-tube the rest, you sound like your smart enough to follow instructions


hope this helps - R

[Infinitiguy19]

I charged the AC in my Q45a. I pulled a vacuum for 60 minutes. recycled what was in the system, Can't remember. The longer the vacuum the better the system. As Maxnix said "I can hang meat in my car".

I just wish my Knock sensors and p**** hose on the plenum were in good shape. Everytime I come to a stop I have to shut the AC off or else the car may stall from low idle. Hell the Active acts funny at low idle.

[marcyprojects]

So before I say anything im just gonna put it out there that I havent been to a shop about this yet, not sure when ill get to it due to time and money. Anyway, did more research into ways I could get the system running on my own, even if it were just temporary until I was able to get to a pro. I was able to find out how to bypass the pressure switch at the dryer the force the clutch/compressor to engage. Rigged up a wire or two, grounded it out to the chassis, and sure enough it worked. I was thrilled to find that rigging it this way did not drain my battery overnight like when I ran direct power to the compressor. I also got a better gauge that read consistently and filled the system to spec.

Now for the bad part. I ran the car like this for the last 3 days and at first everything seemed to be ok but I recently started to notice an affect on the idle. The setup seemed to drop the rpm at idle to around 5-550 with the blower turned off. with the air on and blowing it idled closer to 500 rpm, and a noticable power loss on the lower end. I undid the rig this afternoon and all is good but im back to no a/c again. Compressor still will not engage even though im sure the freon level is correct. Not sure why this is happening? Maybe I dont know enough about a/c systems but im trying my hardest not to have to leave my car with someone. Is it just a bad pressure switch or something else? Why would the bypass cause the motor to run like crap?

[Infinitiguy19]

By doing what you did you may have blown up the whole system. That pressure switch is there too keep the system from functioning till the pressure is at the right spec.