m0ist

Hey ya'll-

So my AC stopped working back in June, and recently the heat has just been too unbearable to drive without it.

When I press the AC button I can hear the compressor for a second or two and then it comes off and the light starts flashing. I went through the diagnostics and it comes back with '00' no faults detected.

I assumed this to just mean that I have a leak somewhere and the system needs to be recharged. I had an old can of R134 and tried to fill it up, however the recharge can quick release fitting did not want to mate to the low pressure fill point.

I figured the fitting on the can must be bad so I went out and bought a new can with a new hose. Same deal. Didn't want to mate with the low pressure line. Basically the hose just doesn't want to 'click' into where the schrader valve is.

I don't really want to replace the whole low pressure hose line. Can I recharge through the high pressure side of the system? Is there a fitting that I can screw into the low pressure line to give me a new fill point?

Any help would be appreciated.

dicer

What kind of car, and year and all that sorta stuff. We have no idea what you are working on. So can't help.

m0ist

Thanks for the reply, sorry for the lack of info-- I thought that was already assumed in the model forum. I have a 1995 ls400 ucf20 with refrigerant r134a.

dicer

Yeah but look at the range of cars for the forum. I wish they would separate the years. If it was a 1990 it could have R12 and is lot different car than a 95, so you have to say what it is you are working on. I don't know 95's so see it matters.

AaronUCF11

High and low ports are different connections. Are you definately trying to connect to lp?

dicer

And if the compressor is running and you try to charge into the HP port you will likely have that R134 can burst and get hurt bad.

m0ist

I was able to release some of the refrigerant from the system. After doing so the hose was able to fit on to the LP service port. Some *** clown at pep boys over filled my AC system to OVER 150psi. The compressor seems to want to run up until I reach about 40psi, and then the AC light starts flashing again and the compressor turns off. Unfortunately with the AC light solid, it did not give me cold air.

However I did get to read a couple codes off of the diagnostic menu and got codes 21, 23, 24.

21 & 24 are solar light sensor circuit code, it was a little dark out so i am assuming that was why they are on.

Code 23 is for "pressure switch circuit". Not sure where this is or what it is.

fixmiester

150 psi static pressure doesn't mean the system is overfilled. But 40 psi when the compressor is running definitely means it's probably UNDERFILLED, and the low pressure sensor will turn the compressor off, until the pressure rises to over 50 psi. If you had trouble simply connecting the can to the low pressure fitting, you need to take it to someone who has more experience and guages, to do it right.

m0ist

When I say over 150psi, it was measured after release a lot of refrigerant from the system. Who knows what it was at before. The quick release hose goes on no problem after I released some of the pressure. No doubt in my mind that it was over filled.

I agree with you that 40psi is probably underfilled. The compressor was definitely running up until I went over ~45psi. Wouldn't this mean the high pressure switch is bad? Correct me if I'm wrong but the high pressure switch would turn off the compressor if the pressure gets too high correct?

fixmiester

Static (system off) pressure has almost no relationship to the amount of refrigerant in the system; it is purely a function of ambient temperature of a saturated vapor. That pressure would be the same, whether you had one can or four cans in the system; it's meaningless. ONLY the pressures measured with the system operating and stabilized are valid.Novices can trash a $2000 system . Get help.

m0ist

So under your logic adding more volume into the system will not affect the pressure if it is not running? Ok

Your response added absolutely no value to my question.

AaronUCF11

Thats not quite what he ment. Pressure changes greatly with heat, more volume should increase the pressure and also the heat.

Really without a set of gauges your flying blind. We have a couple thousand dollar machine at work, it has auto scales to measure refrigerant. I still use those basic analouge gauges to fine tune. I hope your not releasing that gas into the air.