Stereo wiring question

[Jeff G 78]

I am finally getting around to installing a stereo in my '78 280Z and have a small problem. The car still had the original stereo plug and none of the wiring had been touched, so at least I am not dealing with PO nonsense. The problem I have is that I cannot find a switched power lead. The original stereo plug has six pins. They are +12V always on, Ground, Illumination, Dimmer, and LH speaker + and -. There are also two RH speaker wires that are not part of the harness. I have checked every wire and I used the FSM wiring diagram to trace them all back, but nothing comes on with the key in "ACC". I can't believe that the original radio didn't have a switched power wire rather than a full time power since there would have been no clock, presets, etc. to save.

What am I missing? I have checked the +12V lead numerous times and it is always on. For those who have installed a sound system in your 280Z, where did you get the always on and switched power?

[rfaranda]

I know this is an old post but I'm having the same issue.

Can anyone shed some light please????

Thanks.

[Zs-ondabrain]

I would use the FSM to find the Accesory relay, find the output wire and trace it back to the radio area. There Has to be an Acc. wire in that area. Maybe a bad fuse, bad relay or connection??

You can also just tap the acc wire near the ignition switch and run that tapped wire to the radio area.

The other option is to run that tpped wire into a relay (post 85) ground (post 86) connect that battery power wire into (post 87) and the red radio's power wire to (post 30) This set-up will make that tapped acc. wire into a 12 volt signal wire and the main power for the radio will come from the battery. and be switched on by the ignition, via the relay. And fuse the power wire.

Dave

Just make sure to fuse it for safety.

DAve