But Mad North-Northwest
Join Date: Sep 2003
Location: SF Bay Area, CA
Yeah, see, that's messed up. On a Bosch relay, 30 is supposed to be +12v input and 87 is output to the device. If you have 12v on 87 and ground at 30 it'll cause a dead short if the relay coil is triggered. Like I said, I think Alfa screwed up the wiring.
Did you trace the wires behind the radio? On mine there is a separate wire (outside of the plastic harness plug) that provides switched power to the radio. It has an inline filter holder for a glass fuse. That's where the power comes from: the relay does literallly nothing.
Constant power on the red wire should be working, so not sure what to tell you there.
I'm on the road and don't have my wiring diagrams. See what else you can ding out and report back. You know Alfa: it's possible your car is different from mine!
1963 Giulia Spider (1750 engine)
Former: 1987 Milano Gold