2nd Gen Non-Engine/Transmission A/C Issues

[drrhoades]

With my AC on cold it does not get real cold. Not like it use to anyway. The compressor kicks on and off about every 5 seconds or so and when it does kick on it puts the pressure on the low side up to about 45 psi when it is 70 deg F. out. The pressure then drops to about 30 psi then comes back up with the compressor.



Should the pressure be doing this or should it stay steady when the compressor kicks off. Or do I just need to put some more R-134a in it and hope for the best.



Thanks,

Doug

 

[Andy Redmond]

Its likely low on charge or maybe the pressure cycling switch on top of the accumaltor (dryer) and also in the liquid line (hi psi) near the charge air cooler boot/near a/c compressor.



If a 1/2 can helps it, then maybe try a can and watch your pressures. 32-39 low side/200-230 hi side @ 90 deg.



If you need coolant/freon, then you have a leak, get it repaired now, its more expensive later. Find a shop with a good sniffer or uv dye test.



DONT use leak sealers/stop leak, most shops won't recover your system without $$$$$$ it clogs up there equipment.



If you recharge it and its good for a couple of days then no cold air, my bet is on the evap core inside the blower box (dash comes out).



Good luck

Stay cool. . Andy

 

[duaneparks]

FWIW, I had the same problem. Turns out, I have a leak in one of my hoses. Not a bad leak, but it's there and the hose has to be replaced.



Leak was pinpointed by using UV dye that was put in when I recharged the system. It's going to the mechanic after Memorial Day... because yes, they are much more expensive to fix later than now.



DARN DODGE components The leak is nowhere near anything that could have rubbed or otherwise compromised the integrity of the hose. I am my own warranty station too.



Duane

 

[drrhoades]

So do I want my low side pressure to be 40psi when the compressor is off or when it kicks on. I can get 45 psi out of it now when the compressor kicks on but then it drops down to 30 psi a second later.



Doug

 

[B.G. Smith]

Originally posted by drhoades

So do I want my low side pressure to be 40psi when the compressor is off or when it kicks on. I can get 45 psi out of it now when the compressor kicks on but then it drops down to 30 psi a second later.



Doug

With 70 deg. outside temp. and the compressor running the suction pressure should be 35-40 pounds(with a properly charged system). Discharge pressure should be about 135-145 pounds, this would be with the engine running @ 1,000 rpm. The clutch cycling switch mentioned above opens at 25 pounds(stops compressor) and closes at 43 pounds(starts compressor). Of course as the outside temp. or space being cooled temp. goes up, so do the suction and discharge pressures. bg

 

[Matt42]

Originally posted by B. G. Smith

With 70 deg. outside temp. and the compressor running the suction pressure should be 35-40 pounds(with a properly charged system). Discharge pressure should be about 135-145 pounds, this would be with the engine running @ 1,000 rpm. The clutch cycling switch mentioned above opens at 25 pounds(stops compressor) and closes at 43 pounds(starts compressor). Of course as the outside temp. or space being cooled temp. goes up, so do the suction and discharge pressures. bg

The 1996 TSM actually has a useful temperature-pressure chart. By "useful," I mean that it lists pressures for ambient temperatures up to 120* F. It was always a difficult thing trying to extrapolate pressures when the ambient temperature chart ended at 95* F.



I assume that the 1997 TSM will have a similar chart. Maybe the same.