Air Conditioning not getting power

I just took my truck to an AC guy and its fully charged with no leaks. The only way we can get the compressor to kick on is to take the relay out and jump the terminals.

We checked all the switches and they seem to be OK. I took the AC heater controls out to see if I could jump the dash switch but there is 6 pins on it.

Can I run a wire straight to the relay with a switch for now until I get back from the power tour?

Does any body know which wire on the relay to run a hot wire to?

thanks, Kris

1997 GMC LS6 with 305 Accessories.

Also, I put a new relay in it and it didn't fix it

You need Lance's help. PM user NITROUS and see if he can help.

Air Conditioning not getting power - FSC Forum

here is more info about it if it helps

Check your binary switch. aka pressure switch

I have checked all three switches.

thanks

Not all three of them are "jumpable" as a test.

Did you install a three wire F-Body sensor in the A/C high pressure line, to allow the computer to control & cycle the A/C system?

No I'm trying to use the 305 harness to run it.

Please explain in detail I have no idea what I'm doing.

check the 10 amp fuse.. i did the same thing. i felt dumb. deeee you emmm beeee

I checked all fuses and they are good.

Thanks for everyone's help

anybody else know what I can do

You could just tie into the trigger wire with a switched power wire so that its always on with the ignition. When winter comes along disconnect the wire or put a switch under the hood to turn it off. It's rigging but sometimes its your only choice short of paying $80/hr for the dealer to look at it and tell you they don't know what to do but replace the whole harness.

Thanks RedHearbeat

Does anybody know what wire that is and if the compressor would cycle if I do it this way?

Nope, wouldn't cycle. Have you traced all the wires back into the cab? Have you replaced or at least checked the relays that control the a/c behind the glove box insert? Have you replaced the a/c control module on the dash?

There are relays behind the glove box?

I thought the only ones are under the hood.


Is the control module the one with the buttons and knobs for the fan and heat/AC controls? If so I have not replaced it, pretty pricey.

Is there a timed switch(so it will cycle) I could buy and run it directly to the compressor?

Cycle time is determined by low side pressure.