Aftermarket Radio in my '82 GT

[fivebugles306]

I have a aftermarket stem mount radio to put in my '82 GT. I bought the car without a radio in it. It does have the "pull to operate" amplifier. I have found the factory radio plug. Can I get one of the adapter plugs and use the factory harness if I don't plan on using the factory amplifier? The plug coming from my amp switch appears to be the same as the adapter plugs I've found advertised. Or, will I need to bypass the amplifier? I have already installed the new dash speakers and decided to use the factory connectors. Will I be better off running all new wire for all four new speakers?

Thanks,
Jeff

[Travis T]

The amplifier has the same plug on the end as the radio plug does. It really just plugs in between the radio and the harness so it has the same ends on it.

[fivebugles306]

I think I'll order one of the adapter plugs and give it a try............ Thanks

[Boomer85gt]

I replaced all the wires going to the speakers. I don't trust that old stuff in there.

[grabbergreen84]

If the aftermarket radio has a higher wattage, like more than 7 or 8 watts per channel, I might worry about the factory amp, and want to run my own speaker wires. IIRC, the Premium Sound in my '82 only amplified the rear speakers. After a while, I went with a trunk-style amp, and ran my own wires, and didn't use the PS amp..
My '84's factory PS amp drove all four speakers, and worked fine with a low-power aftermarket stereo.

Beware of the light blue-with-red stripe wire which runs with the yellow 12V+ wire. The blue one is a gauge light lead, and you only want to use it if your aftermarket radio has an illumination input. n00bs use the blue one as a ground, and wonder why their gauge lights and tail lights don't work.

You might still be able to source a rubber or plastic filler-panel to fill any gaps between the factory opening and the "dial face" area of the aftermarket radio.

[JACook]

What you need to do will depend entirely on the speaker wiring in the radio you are wanting to install.
The factory PS amp expects all the channels from the radio to have a common ground. Many aftermarket
radios use differential amplifier output stages that will be damaged if you try to connect one side of the
outputs together. If your replacement unit has eight speaker output wires, it is likely a differential output,
if there are only five output wires, it's not.

If you have eight output wires, it's unlikely that the four (-) wires would be common, but not unpossible.
If the unit does not have specific instructions about the speaker wiring, the easy way to tell for sure is to
measure for continuity between all four of the (-) outputs. If you don't have <0.1 Ω between them, do not
connect them together.

The good news here is, since your car came with premium sound, if you do have a differential output radio,
the factory speaker wiring is already capable. You would just need to connect in using the goezoutta connector
on the amp switch.

If your aftermarket radio has five output wires, or has eight, but the four (-) wires are common, you can use
the existing radio harness connector to tie in. The '81 PS amp powers only the rear speakers.