A/C clutch relay

I have a 1995 Firebird Formula, with the manual 6 and LT1. Sorry for posting here but this forum has more traffic than the Firebird forums.

My problem is with the A/C clutch relay. It will not allow the a/c clutch to activate. I tryed a new relay and tested the old one they are both fine. However I can get the clutch to activate by taking a jumper wire across the
B1 to B4 terminals. (This completes hot circuit to clutch). So then I assume the trigger circuit in the relay is not getting completed, but if I put my volt meter postivite on the B2 terminal and ground to the B5 terminal I get about 13 volts which is plenty to pull the relay in to allow current to flow through the B1/B4 circuit path, but still not luck. So why does it work if I jump B1/B4, the relay looks to be accomplishing the same thing, however I haven't removed the fuse block so I could back probe the relay wires to see what I learn there? Any help?

Thanks,

randy

Sounds like you are low on refrigerant charge in your A/C system or have a defective pressure switch.
If so the compressor will not engage - this is to protect it from being damaged due to the lack of lubrication. This is controlled by the pressure switch on the A/C system located on the low pressure side. This switch also protects the compressor from lockup from refrigerant returning as a liquid instead of a gas.

I actually have set the pressures properly while jumping the relay. However, I don't think its the pressure switch, because just jumping the pressure switch changes nothing.