it could very well have been a Roll Along. it had the rear window that slid down, but I didn't take it because the mechanism was completely jack

 

The roll along trucks had roll down back windows? Like the Tundras?

 

Found the info on them pretty cool. I never new or was an option back then on these trucks

 

back then, speakers were either in the dash or rear deck. no speakers in the doors.

 

I attached a pic of the factory amp. I have an '96 F150 Eddie Bauer that came with the premium sound system, which includes the factory amp. In the pic, you will see the results of a car stereo installer that doesn't know what he is doing. I wanted an aftermarket stereo installed so that I could plug in my i-phone into it. I am not a pro, but tried everything. I finally bought it to a "pro". He said they couldn't do it unless they "disconnected" the amp and hooked up speaker wires directly to the stereo. I really didn't care that the amp wouldn't work - I just wanted to play my song lists. So, after getting the truck back, this is the carnage that ensued. really not that big of a deal - if I want everything back to stock, I'll just have to get new harnesses.
So, anyway, this is what the amp looks like and where it is located (that is the gas pedal throttle linkage going through the firewall).

 

That's true

 

I wanna say my 87 T-Bird and 88 Bronco II both used chassis ground for the speakers. I'm sure at least one of them did because it was the first time I saw that setup and it took me a couple minutes with a meter to figure out what was going on so I could put in my insanely powerful 30W cd player from walmart.

Oh and good to know about that factory amp. Thanks for the pic!

 

I know on my 88 F250 I had to run new wires to the front door speakers. The factory wiring would not work with the adapter. The grounds are run different, I have been installing stereos for 25 years and have found this problem alot on the older fords.

 

I had to switch the left and right front speaker ground wires on my truck with an aftermarket radio. They were opposite of the adapter which made it so I couldn't adjust the balance left to right. I think I had to do the same thing on my dad's '92.

 

HOW are the grounds different?!?!?

You have a "+" and a "-" going from the radio to each speaker

 

ive installed two diff aftermarket radios and used factory wiring for the door speakers which were aftermarket and everthing worked fine has to be a bad wiring harness from factory wiring to aftermarket harness to radio idk about these ground issues everyone is talking about all mine worked fine with stock speaker wires and aftermarket head unit and aftermarket speakers

 

Brad, the left ground of the adapter harness went to the right speaker and the right ground went to the left speaker. Ford must have changed the wiring at some point during the model run and the aftermarket adapter harness is supposed to work for the entire range.

 

Interesting... My truck does the same thing with an aftermarket HU. I have yet to tear in to it though. I've just assumed the PO wired it wrong or used the wrong adapter harness.

I'll be watching this to see how it turns out so I know for when I'm ready to get into mine

 

Ok, then the harness is wrong. They make the RIGHT harness to BYPASS the stock amp

 

So I drove around with only sound to the back for a few days before I was bugged enough to go buy new 6.5" Pioneer 3-way speakers for the doors. I got them in (no mods, they fit perfect) and now they all work great. No issues??

I don't know what was going in and why but glad it's behind me.