HI folks.

I have a 86 L98 . I noticed my A/C wasn't working and checked the system. I have a good fuse, 12 volts to the compressor and a full charge . If I run a wire to the battery, the compressor kicks on no problem cold air out of the dash. When I plug the harness in although I have power nothing happens when I switch it to A/C in the dash. I don't have the electronic controls. Any idea what to look for??

Lots and lots of possibilities.

1--Though your system does have refrigerant; is it enough?

The low pressure switch will stop the compressor clutch from engaging if not enough refrigerant.

2--Your fuse is good, but are the relays good?

Start with those two.

Thank you for the advice, Yes I have a good fuse, Yes I have a full charge of refrigerant . I didn't see any relays in the system. Do you know the location of this relay? I do have 12 volts at the plug when the A/C is on but it doesn't start the compressor. If I run separate wires to the compressor from the battery it will start up and run cold air in the cabin. I'm stumped

1-Is the low pressure switch still good?...high pressure switch?

2-I don't know for a fact if your year model has relays.

3-Try running a separate ground since you do have 12V at the compressor.

>Check if the two (if applicable) pressure switches are working correctly.

>If those work correctly, then it's checking the electrical circuit that energizes the compressor clutch, this includes the ground circuit.

These are all free checks and takes no time at all.

Thanks for the help, it looks like I may have a relay in my system according to the manual although its must be in a good hiding spot. I've checked everything you recommended and still no luck. I'm going to replace the relay when I find it and if this doesn't work I think Ill take it to the shop. I appreciate your help with this.