I found a power antenna in the shed I forgot I had. If I installed it, is the wiring in the dash to hook it up, if I also installed the switch? Anybody have a power antenna switch for sale? Thanks.
The switch has the wiring for the antenna attached to it. I have some of the switches as well. I'll ship you one for $40.
50RACER,
Where does the switch get its power from? Is the connection for it already there in the dash? Thanks for your offer. I'll let you know when I might be able to buy it. Thanks.

The red and green wire that are together go to the antenna. The two black wires that are in the same connector, I believe, are the ones that power the switch and they plug into another connector in the area around the back of the radio that is part of the much larger dash / fuse panel harness. You probably have to pull out the radio to locate it.
In the 86 EVTM, looks like the yellow/black stripe and black wires in connector C303 are the power and ground to the switch.