Just finished swapping a bad compressor, started it up turned on the ac and nothing. Checked the wire connected to the compressor and it's not getting any power. The light on the ac button stays lit on green, and I checked the fuses which are all fine. It's just not getting power, any ideas what it might be?

THanks

 

Low refrigerant could cause that symptom

 

How would that cause this problem? I don't think their's a sensor that monitors the refrigerant amount in it.

I haven't filled it up yet, I was gonna do that next but since it doesn't work at all I wanted to fix this first.

 

I just added some from a bottle I had laying around and it turned on! thanks tanacoma

 

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Yes, there IS a sensor.
I'm glad it was just that simple for you.

 

Did you evacuate the system before adding the refrigerant?

 

on my 88 single cab 4x4 the pressure sensor in under the kick panel on pass. side mine blew while waiting in line to get food lol i thought i'd blown a coolant hose but nope a/c pressure switch cost me all of $9.00 bucks but the best part was i already had the whole dash out redoing the dash and well heck i ended up repainting/covering anything that needed TLC. i am running the 22re and dont get me wrong its a great motor and would prob run on 2 of the 4 cylinders if need be. i k ow when i bout mine i thought damn this thing is slow until i seen #2 cylinder had all of 60psi on a good day wet or dry test... while 1,3,4 was around 160psi... its all fixed now but if i had know then what i do know i would have pulled the 22 sold it and would now be cruising with a non vortec GM 4.3!!!! 3 times the power and around the same cost. motor fits like a glove and i could still use all of my drive train.... ya live and ya learn

o and i had to use a 90 a/c fitting when i installed the ac on mine, it made it sch easier to charge and get at... well good luck buddy

 

Low refridgerant = low pressure = no AC for you. Glad you got it fixed.