I've recently put a kenwood deck (KDC-5018) into my '90 GT4 and i'm having trouble getting the electric antenna to go up...i tried connecting the antenna wire to the black/red stripe wire which i believed was the correct one but nothing happened..any ideas? It used to have an AKAI deck in there but the antenna didn't work then either..
Get a wiring diagram for your car.
Find the two wires that provide power and earth to your antenna.
Put 12V to the power (use a battery charger or your own battery),
and connect the earth to earth and see/hear if the electric motor is whirring away.
If it is and no up/down, disassemble and check the drive belt.
If no whirr you would suspect the electric motor is kaput.