ken72

When I turn mine on it blows cool not ice cold but I never had a car that blows cold at idle. Anyway, I can hear / see my clutch plate kick on then off. It seems to do this every 5 seconds or so, just clicking on and off. Is this normal operation? I know someone said it could be low and I tried to fill it but I could not get to fill, I just could not get that stupid can and guage to work. How does everyone elses A/C system work?

LCFRJEEP

As far as I know, my cycles on and off like your describing. I think thats normal but im not completly sure.

ken72

thanks lcfrjeep. I hope it is normal, but I have not heard a compressor kick on and off that much, then again this one has a much louder click than I have ever heard in any other vehicle I have owned as well. I am hoping to hear from other members just to either confirm the cycle is correct.

gsperaz

My 2001 4.0 also cycles on and off. With a gauge on the low pressure side, it cycles from 25psi to 40psi about every 10 seconds. From what I have read this is normal operation. Does not blow ice cubes but cools the XJ for a comfortable ride. Maybe someone who knows for sure will chime in.

ken72

Thanks Gsperaz, I wish I could get that stupid gauge on that can of freon to work so I could test mine correctly. I still think mine is low, I just cant get the can or guage to work properly. It drives me nuts, I think I am going to have to break down and take it to an A/C specialist.

gsperaz

Ken72, Let me know what you find out from the A/c guys.

ken72

will do, I dont know when I will have time to do it, but it will have to happen soon I guess.

ken72

Ok here is my update on this. The temps here in Tennesse just got too warm for no A/C so I thought I would give this can of r134a in my garage another shot. I hooked up the guage and the pressure would hit 40psi with the clutch engaged and then drop to 20 or so with the clutch off. The clutch kept cycleing on and off so quickly and I had not so cool air comming out that I decided to open the can and let if feed the low side port. After about a few seconds of feeding the clutch kicked on and stayed on, no cycling on and off. The guage read a steady 25 psi and I wasnt sure if I was feeding too much. I did not see the guage move much so I unplugged it and checked the air. It was much cooler and the clutch seemed to cycle less and quieter. Its still not ice cold like other cars and I could probably feed it more but I thought I would stop while I was ahead. Should I have feed it more to see if the guage would move any or was it best to stop after the clutch kicked on and stayed on? Like I said the air is cooler so maybe I will see how far that gets me... any thoughts?

ken72

On a side note, I went out to check it and the air cooled quickly but just not ice cold... cool enough for me though. Think I should try and load more and get it from the 20 or so psi to 30 or 35 psi?... or just leave well enough alone.

Hommersimpson

when you are reving engine at 1500... it needs to be somewere around 20.. you have a site glass ontop of dryer... if you see bubbles its low... so ad some more..

ken72

Thanks Hommer but I dont think there is a site glass on the dryer. I could be wrong but I cant find one.

MachRanger

I just re-charged my '99. The clutch was cycling on/off every 5 seconds too. I added R134a up to about 30 psi (all it would take) and the clutch stayed engaged. The air blows colder than before. I couldn't find a site-glass either. Looked over every line on the a/c system and couldn't find one.

ken72

Thanks Mach. Maybe I will go back and add it until I get up to 30 psi. It is cooler but I can tell it could use some more. Thanks again!

OldMan

CCOT - Cycling Clutch Orifice Tube - system.

In a CCOT system the freon is metered through a tube with a narrow opening. Pressure too high, clutch off; pressure too low, clutch on.
Cycling every 5 seconds is too fast. Could use some freon, because eventually it'll stop cycling altogether and stay off.
If you put a gauge on the low side (That's the big hose) you'll read about 30 PSI + or - and you can see the pressure fall, then rise when the clutch kicks in.
High side (That's the small hose) depends on the temp but can run up to about 250 PSI. Maybe even a bit more.

Your temperature at the vent should go to about 40-42 degrees and stay there. That's using the recirculated air in the vehicle with plenty of air blowing across the coils (use a big fan) after everything has stabilized. Temp in Pheonix may be a little higher

ken72

Thanks for that! These systems are not hard to understand but without any realy knowledge they are very tricky. I need to go back and try to add more to my system I think. The PSI's are a little low still.