No A/C - FAST related?

[turbojimmy]

Maybe this belongs in the Performance ECM section, maybe not.

I can't remember the last time I used my A/C - whether it was before FAST or after FAST was installed. In any event, I don't have any.

My compressor had gone bad a couple of years ago, but I ran it occasionally anyway. It sounded awful but still sort of worked. I noticed this year when I tried it the clutch wasn't engaging. No big deal, needed a new one anyway. I installed a new compressor and have the same problem - clutch isn't engaging.

When I jump the low pressure switch the fans kick on, but I don't know whether that's all done under the hood or whether the ECM has anything to do with it (again, I have FAST XFI, not stock ECM). Looking at the factory service manual, the ECM appears to have something to so with the A/C compressor circuit so I'm wondering if my problem is with FAST or did something else go wrong?

Any advice would be appreciated.....

Jim

 

[Otto J]

im pretty sure if it comes on when jumping the switch that its either low on freon or the switch,Try adjusting the switch if you know its full or freon,There is something that has to be grounded when an XFI is installed but Caspers does this in the jumper harness.
Also open you XFI software,go online,hit F9 and look for the A/C Flag and turn it on and off and see if it changes from 0 to 1.
This will let you know weather or not the XFI sees the A/C command

 

[turbojimmy]

im pretty sure if it comes on when jumping the switch that its either low on freon or the switch,Try adjusting the switch if you know its full or freon,There is something that has to be grounded when an XFI is installed but Caspers does this in the jumper harness.
Also open you XFI software,go online,hit F9 and look for the A/C Flag and turn it on and off and see if it changes from 0 to 1.
This will let you know weather or not the XFI sees the A/C command

Thanks Otto. Turns out I'm just a dope. I tried a new .GCT file last fall but neglected to check the a/c parameters. It occurred to me right after I hit the "Post" button. They were set to shut the compressor off when the coolant temp reached 11 (eleven) degrees. Oops.

The system is totally empty (except for the oil I put in it). I had to flush it and replace the accumulator because the compressor grendaded. I needed to run the compressor to suck in the new refrigerant. Funny but the new compressor doesn't sound like a box of rocks like the old one did. Must be something wrong with it

Jim