74 TA stereo with 8 track wiring diagram

[twov8sandat4]

Hello everyone,

As part of my Vintage Air install, I am restoring as much of the interior as I can.  My car came factory equipped with the AM/FM Stereo and 8 track.  At some point in its life, the radio was replaced with an Alpine head unit and the factory plugs and harness for it cut and removed.  I found the correct radio to 8 track harness on eBay, but I don’t have a wiring diagram for the setup which would include speaker connections also.  There are a few harness routing diagrams online that show where the plugs go,which are helpful, but I need the actual wiring diagrams as there are different ways of connecting the harness from what I understand.  My factory manual does not have the diagrams for some reason.

If someone has it and can post it, I would greatly appreciate it.

[b_hill_86]

I probably have what you need but what are you trying to accomplish exactly? Just reinstalling a factory radio and 8 track using a factory harness?

[twov8sandat4]

I probably have what you need but what are you trying to accomplish exactly? Just reinstalling a factory radio and 8 track using a factory harness?

Yes, I am trying to reinstall the factory radio and 8 track using factory radio to 8 track harness that was missing (just got one on eBay).  Connecting that harness to the body harness is the issue as the original speaker connectors and wires look like they are gone.  I found the original 3 prong body connector that has the yellow (power), gray (light) and an empty slot for what should be the rear speaker lead but no terminal or wires are gone in it.  Just trying to figure out how the factory wired this and see if any of the original connectors and wires are buried somewhere or if I have to hunt them down to make everything work like the factory did.

Thanks.

[roadking77]

A diagram would be nice to have. I have the am/fm and separate 8 track in my 77. It has never been hooked up. After the ordeal I had with the Digital radio with power antennae I figure the standard am/fm should be a breeze I plan on digging into that before too long. Almost everything works on my 77 with the exception of a couple of things. The radio being one of them.

[Wallington]

I've seen wiring diagrams for 8-tracks in early manuals, console and rear. Not sure which, can locate if desperate. Also have saved pics of NOS and used harnesses. But then again, anyone can feel free to spend years saving pics for future use of others and purchasing every manual so that they don't ever need to ask basic questions without looking it up first.

[twov8sandat4]

A diagram would be nice to have. I have the am/fm and separate 8 track in my 77. It has never been hooked up. After the ordeal I had with the Digital radio with power antennae I figure the standard am/fm should be a breeze I plan on digging into that before too long. Almost everything works on my 77 with the exception of a couple of things. The radio being one of them.

The 8 track and clock are the only 2 things not working in mine…. Hopefully I’ll get the 8 track working.

Thanks.

[twov8sandat4]

I've seen wiring diagrams for 8-tracks in early manuals, console and rear. Not sure which, can locate if desperate. Also have saved pics of NOS and used harnesses. But then again, anyone can feel free to spend years saving pics for future use of others and purchasing every manual so that they don't ever need to ask basic questions without looking it up first.

Must be tough to be omniscient 🤪😁

[b_hill_86]

The difference in hooking up, to my knowledge, only had to do with what setup you have paired with the 8 track as in whether you had an AM only, AM/FM mono, stereo and one or two speakers I believe. I think adding the player dictated two speakers automatically. All of that is handled by the harness though I’m told. There were different harnesses depending on the setup. I can try to send you what I have for 77. I think 74 should be the same but I’m not positive.

[firebirdparts]

I have that.  I thought I might have posted it, but I may be remembering pre-crash.  It looks like it's not in the 74 manual, but I am pretty sure I have it anyway.  I am posting the 77 version which I presume is the same.  Two versions - some radios are mono.



The thing to notice here by observation is that the radio speaker wires were playing physically through the 8 track, but it's an ordinary radio with an amp.  It's just passing through the tape player.  When you push in a tape, the tape player just takes over the speaker wires and the radio gets cut out.

[roadking77]

Thanks for posting that. It will be helpful.

[Wallington]

Oh, forgot. Probably what I had seen anyway.

[twov8sandat4]

I have that.  I thought I might have posted it, but I may be remembering pre-crash.  It looks like it's not in the 74 manual, but I am pretty sure I have it anyway.  I am posting the 77 version which I presume is the same.  Two versions - some radios are mono.



The thing to notice here by observation is that the radio speaker wires were playing physically through the 8 track, but it's an ordinary radio with an amp.  It's just passing through the tape player.  When you push in a tape, the tape player just takes over the speaker wires and the radio gets cut out.

Thanks Firebirdparts.  That is gold.

Since the original wiring harness on the body side for the radio and speakers was missing, I was trying to make sense of the replacement radio to 8-track harness I got from ebay.  The radio is an AM/FM Stereo per the PHS.   

I found the body side 3 pin plug that provides power and light to the radio.  It was cut and bypassed to wire the Alpine deck directly.  I restored that plug to carry the yellow (power) and gray (light) wires and ordered the plug and wires that go from there to the radio.  This wiring diagram is going to help me tremendously to restore the audio back to factory.

[Wallington]

Possibly same thing, from the 1973 Service Manual.

Firebird 8-track diagrams 1973 (2) by Ben Noakes, on Flickr
Firebird 8-track diagrams 1973 (1) by Ben Noakes, on Flickr

And NOS harness, #8903824 1970-75 ALL - EXC STEREO RADIO

NOS GM 8-track  radio harness 8903824 (1) by Ben Noakes, on Flickr