Rear Speakers Only Put Out Static

The stock speaker system is weird in that it shares the chassis ground with the audio ground…iirc.

Some possible ideas:

Check for bad ground points causing noise in the system.

Using the stock stereo, it very well could have gone out. I've rescued several from the junkyard in the past, looking for a good one only to find
it doesn't put out sound, but lights up and finds radio signals. 30yr old electronics have issues, from my limited knowledge,
it's usually faulty capacitors in the radio but, idk which ones. There are a lot.

Using an aftermarket stereo and the stock wires, try running new wires to the speakers from the head unit and do not use the stock harness
for anything but steady 12V and switched 12V supply. This silences bitching Betty on the front left speaker, but you could put a small speaker under the dash
to the left of the drivers column where there is a cavity and wire the speaker to the stock left door speaker wiring to hear her lovely voice again.

Using an aftermarket head unit, wires and speakers…see #1

Come to think of it, I don't remember ever having a fully functioning stereo on a Z31. I had a feeling it was a ground issue when I put the working speakers in from the 85 and I still got static. There's also that whirring noise whenever you accelerate or decelerate. Tried a noise supp. on the alternator, but that didn't work either. This makes me think that there is an internal noise suppressor on the factory stereo.

Spider senses tingling. Think I'm going to have to remove trim pieces again to find the bad ground. Here's the funny thing about cars. One type of car, like the Z31 you never have a working radio. On the other hand, the 2000 Toyota Corolla has a stereo that works perfect. That car is almost 20 years old. Not as old as the Z, but it's still up there. However, it burns oil but I have never had a Z31 that burned oil. So Nissan VG30 engine good seals; and Toyota Corolla good radio.

I'd like to keep Betty around if I can. Makes me feel like the car is alive. Almost like the car from "Christine"I suppose haha.

What year is your Z? On the 50th AE, it's almost always cold solder joints in the head unit which will cause one or more of the speakers to drop out or not work altogether.

Greg

It's an 84 GLL.