So I have a 99 Civic LX, a/c wasn’t working when I bought it. I did all the troubleshooting to make sure that the compressor was working. As far as I know it is working, the clutch engages when it should and if I put a paper clip in the fuse box it makes the clutch spin continuously. I put in a dye to look for leaks, turns out my evaporator was leaking. I replaced that and the expansion valve(figured I might as well). Got the system recharged by a mechanic and everything was working well. Had the air conditioner getting all the way down to 60F. Wouldn’t really go lower than that, and I live in NY, where the hottest its been so far is 90F. But the A/c would cool my car very well. That worked for a few weeks, and now it stopped working all of a sudden. The clutch in the compressor still engages and I’ve looked for leaks every where and I have found nothing( the psi level still the same as well). Condenser fan runs but the Low line isn’t getting cold anymore and it should. And the High line is warm/hot to the touch which is normal when the ac is on. So I am thinking that there’s a blockage somewhere, I’ve read online that it could be a blocked condenser. I don’t have a IR thermometer to get a reading of it. Should I just replace my condenser and go from there or overhaul the entire system? Is there something I’m missing? System is properly charged. Compressor spins. Fans are spinning. No leaks. But my evaporator isn’t getting cold at all anymore and it used to. I also hear my expansion valve hiss when it is working ( not a leaking hiss, but the sound it makes when it lets the refrigerant through), I don’t think that could be the culprit either

 

Can you describe exactly what the mechanic did to the A/C system when you brought it to him?

Was the receiver dryer replaced?

Was the system fully evacuated and leak tested?

How much refrigerant and oil was added to the system?

Was the system performance tested on a machine?

Can you also explain why you don't think the A/C system has a leak and why you think the system is still fully charged with refrigerant?

 

He used a gauge to vacuum and refill the system . But it was one of those modern machines that have wheels, I forget what they’re called. Its all computerized and you put the specs for the system you’re recharging.

The dryer was not replaced, so far only the evap and expansion valve because the evap was leaking. I wanted to start replacing parts from the inside out. And since replacing the evap fixed the problem at first. I stopped there.

The system was evacuated and leak tested, it worked well for a few weeks. I have a uv light that I use to check for leaks and the only place I find the dye is on the port to recharge. Not that it’s leaking from there, its just whatever was left over from when we recharged it. And when we checked the gauges everything was fine. If I change the condenser I’ll change the drier as well. But I’m also inclined to changing the compressor while I’m at it. No sense in recharging it every time I replace one part. Might as well replace all. I really don’t want to change my compressor because its a little pricey compared to the other parts in the system and I also don’t know a reputable brand I can get one from.

 

Did you tell the mechanic that you did not install a new receiver dryer? Replacing the receiver dryer is a must whenever the the A/C system is opened.

The mechanic or you? Done after A/C did not cool well? Under what conditions did you check the pressures? What were the high and low side readings?

 

I did not actually, I just told him to vacuum and refill the system. should I replace the drier instead of my condenser ?

He checked the gauges(with same machine used to vacuum and recharge). They were the same as when he first refilled it. I am unable to answer the last two questions since it’s something I do not remember. Out of curiosity though, if the readings were off or different, what would that tell you? Besides it being a leak, would the readings tell you if the compressor was bad or another part in the system?

Might I add, the vents blow the same temp as they do with the ac off. Its not like turning the ac on is making the air out of the vents hotter or colder. No change in air temperature

 

If the air from the vents was not blowing cold, the pressure readings on the low and high sides would immediately tell him the likely cause of the problem. Did the mechanic suggest any possible reasons?

When this^ is happening, is the condenser fan running? Is the compressor clutch engaged?

 

Mechanic said its a blockage somewhere. The Low line isn’t getting cold at all, and it used to. it would have condensation build up around it at times. There’s no condensation or change in temperature on the Low side anymore.

Yes, the condenser fan is running and the clutch is engaged. Even when I rev the car up, nothing happens. That used to make it blow a little colder(revving).

 

Should have mentioned this^ in your first post.

Before you attempt to repair an A/C system, you need to do your homework.

Based on the information, you need to start all over again. If you want the A/C system to work properly for the longterm, you would be wise to buy all new components: compressor, condenser, evaporator, expansion valve, receiver dryer, and oil.

But before you install the components, you also must thoroughly flush all the existing A/C lines. Also test the A/C pressure switch and the A/C thermostat. If you don't do the homework, then let a reputable A/C shop do the work for you.

Good luck.