ac help

Is it iceing up an starting to blow warm after some time? may need a bit of freon added, OR temp controler behind Left RT. dash panel 2 wire plug in part.

 

Expanison valve could be froze up also..

 

unplug the cable that goes to the compressor and listen for the click.. when power is applied the magnetic coil engages the compressor clutch on the pulley.. if it's engaged constantly then chances are the clutch is jacked. so if you unplug it and remove power and you don't hear the noticeable click letting you know it disengaged, then you need a new clutch..

 

is the clutch brand new? they're two separate components. you can buy a clutch and use the same compressor, or buy a compressor and use the same clutch.. if you heard a click when plugging it in with the power off, then you most likely have a short with that cable which is allowing the compressor clutch to get power and engage so no matter what the system tells it (engage disengage) it's always going to engage.. time to whip out the multimeter and start tracing wires.

 

no biggie, hope you find it. also, i think there's a fuse for it also.

 

you might try using a jumper wire on the high pressure switch(mines under the windshield wiper tray on the passenger side) and see if compressor engages seems to have been a problem on my trucks good luck

 

if the ac compressor clutch is staying engaged/locked in, make sure the key is off and see if you can spin the outer part of the clutch, you should be able to, if you cannot spin the front hub of the clutch with the key off, pull the panel off above the fuse block on top of the dash, there is a relay in there labeled hvac, pull that relay out and see if you can turn the ac clutch by hand, if you can with the relay out but cant with the relay in, that hvac relay is bad. they are notorious for going bad on the century/Columbia's, and when they stick open they send power to the clutch at all times. it is a 5 prong relay, about $5 at freightliner.