96 C36 Strange A/C Reading

[mbsickness]

Hello all. I have a 96 C36 and the other day the A/C gave me some trouble. I was driving in stop and go traffic (0-5mph) in 95 degree heat. For fifteen minutes the A/C stopped working. The blower fans worked fine...just no cold air. Since I was stuck in traffic I entered the PBU and where it displays the freon pressure and I got "CLO". After traffic picked up speed (35mph) cold air once again returned and the pressure reading was now 128. Any Ideas what "CLO" means? I am hoping this was something simple like the evaporator freezing over and having to defrost. Thanks in advance.

[jnenad16]

if the ac got colder after you started moving, that means you are probably low on freon. as for the CLO and 128, I cant tell you because I dont use/rely on the ac control unit's self diagnostics. I also cant tell you exactly what the possible cause of this is until the system gets hooked up to the ac manifold and the operating pressures are read out.
as for your car running 95degrees, you definitely need to do my lower thermostat and electric thermoswitch mods. do a search, its been discussed quite a few times. coolant flush wouldnt hurt, either.

nenad

[mbsickness]

Thanks for your reply. The car was being driven where the ouside temp was 95 F the engine temp was running at about 85 C. Once traffic picked up to about 20 mph the A/C kicked back in. The AC has been working since that one incident even at idle and is quite cold. I'll hook up a guage to it tomorrow and see what the system pressure is...any idea what the PSI reading should be?

[jnenad16]

with the ac off, the rest pressure should be between 50-100psi at the high side port. when you turn ac on, the operating pressure at the high port should be at least 150psi or higher, and the temp at the low port should be 40degrees. the high side readout should increase and low side readout should decrease as engine rpm's increase.

nenad