hey guys im new here and i have a 2000 chevy blazer ls 4dr 4wd. i bought it without the ac working and im ganna try and fix it and it turns out the compressor works and it does hold freon. i found out the the cable that plug into the compressor has NO power at all. could this mean that the heater ac controls is broken and needs replacing? any ideas help
thanks

 

I'm assuming you're talking about the clutch plug on the front and not the high pressure cutout on the back of the compressor. Power to that is controlled by the VCM and I don't think it has power unless the motor is running. Fuses to check in underhood block: A/C and IGN E. Does your horn work? If so try swapping the horn relay with the A/C compressor relay in the underhood block. Under your hood by the heater box is an aluminum can (reciever) with an electrical plug attached to it. Disconnect it and jump the plug with a small piece of wire. If the compressor takes off you need more freon of the switch is bad.

 

yes the horn works and yes ive tried switching the relays and yes all fuses were checked and were ok, and if you are talking about the plug on the front of the compressor (the one you can see) then yes. one thing i forgot to mention is, we have gotten the compressor to work by jumping it when we connect it to the battery

 

I should've asked if you have the automatic or manual controls. Either way on the back of the compressor is a 2 wire plug, LT BLUE and DK GRN/WHT. Disconnect it and with the truck running check for 12V at the light blue wire when you have the controls in an A/C position. If you don't have it then it's a wiring problem (assuming all fuses are good) or you need to replace the heater control. If you have 12V then try jumping the 2 wires in that connector and see if it starts running. LT BLUE comes from the heater control, DK GRN/WHT is the A/C request to the VCM.

 

i have manual controls and we did hook it up to a meter and it showed nothing so we know the wire has no power. i havent yet gotten a different heated/ac switch but im hoping thats the issue cause it seems to me that if the wiring is bad that would be alot of work

 

Your range switch puts 12v on that wire in any A/C position. I think from fuse 9 in the IP block HVAC1 (I'm home now, don't have the schematic in front of me)

 

ok well i doubled checked the switch and there was 0v in it and i checked the fuse and it was good

 

hello everyone.
I am having the same problem. No power to the cable that connects to the compressor. All of my fuses and relays are ok. Is it problem with the unit inside the car? The heater controls? (not sure if that is what it is called. Please help.....

 

i know that im the one with the same problem as you, but from what ive been finding out is, if all the fuses and relays are ok then you may just have to run to a junkyard and pick up a different heater/ac thing and try that and if that doesnt work then you're not down a lot of money.
but the temporary solution im ganna use is that i went to radioshack and picked up a switch that im going to mount to the bottom of my dash and i may have to go to the junkyard anyways and cut off that compressor cable from another blazer or similar model that is 3-4'' in length and use that for the compressor switch

 

I love it, that's my style of temporary fixing too. Connect to the light blue one and keep that switch in play. I'd thought about suggesting that but decided to stick with "proper" answers. <G> I remember a lot of imports used to have that A/C switch on the heater controls.
Gonzalezllg: You didn't say what you're driving. If it's older I can't be much help, I don't know where the right relays are or have a schematic. Which cable are you talking about that has no power (front or rear)?