This wire was taped off and not being used. It runs out of the harness with the wires going to the starter. Anyone know what it is? Car is an 84 Firebird. 5.0 5 speed.

 

its the altenator wire

 

Still trying to figure out what this is for?

 

Judging by the connector, I would say its power to the high speed fan relay. It may not have been used if the car didnt have AC.

 

Car does have A/C but it was not hooked up when I got it. Where would this plug into?

 

There should be a relay attached to the HVAC housing, in the engine bay, with a large connector matching the one in your photo. The circuit may have an inline fuse for overload protection. I can only make an educated guess as my diagrams for the 84 are vague at best. Since you own an 84 and obviously do your own work, you should really invest in a factory manual for it. They have excellent diagrams.