91 mustang radio amp problem

[BlownPony]

okay so i baught one of those wiring harnesses for my mustang and i looked behind the radio and realized theres an amp there, i hooked up the wires like im supposed to and its not working...i beleive the amp needs to be tunred on for it to work at least thats how it was in my dads 94 mustang....so someone please tell me how to fix this so it all works.. thanks

[BlownPony]

well its all plugged in right and all the colors match going together but the amp isnt turning on...

[BlownPony]

its not that i have no volume the speakers just dont work all together....nothing happens when u turn up the volume and u plug the stock radio in and it works just fine

[Greg@GLD]

its not that i have no volume the speakers just dont work all together....nothing happens when u turn up the volume and u plug the stock radio in and it works just fine


There are two styles of radios- "Premium Sound" and normal. The Premium Sound radio does not have any sort of amplifier inside it, so it would not work without the matching amp. If you have a Premuim Sound unit, it should have a soild dark blue wire coming out the harness, and that wire provides power to the amp only when the head unit is switched on. That's how the amplifier powers up, so look for a solid dark blue input to the amp and and make sure it provides 12V to the amp...

It sounds like you do not have the correct radio "head unit" to work with that amp.

[JORGE]

or just run speaker wire to the speaker from the deck .
that just bypasses your stock amp it'll sound better i think i did the same w/ my stangs ,thats if your going w/ a aftermarket deck

[fivonut]

You can also trace teh wires and remove the amp from the system. If you're using an after market head unit you should have no need for the amp anyway. I had a similar problem with my 86 and after I removed teh amp from teh system and plugged teh adapters into the harness that the amp was plugged into it worked perfectly. I think the amp uses a common ground for the speaker input and that's part of the problem.

[Overdrive]

When I did the stereo in my LX. I ordered it from Crutchfield. When I opened up the box it had a "Install Kit", which contained a wire harness that plugged into the factory speaker lines. It was labeled as a "Factory Amp bypass harness". Here is the part number that I used (#120705008). Worked great.


There isn't a common ground for any of the 6 speakers that I found. And the last owner hacked the living @#$% out of the electrical system. I spent a good amount of time removing wire nuts and twist and tape connections. If I only had the pictures.

Like Greg said there are two lines a black cable with a gray end and a blue cable with black end. The blue cable is the power, signal and speaker lines. This blue cable goes from the head unit to the Amp. At the amp side there is a black connector the leaves the amp and goes to the speakers. this is the line that you have to get a adapter for it. The Amp in the Mustang is a special amp that requires the factory headunit. I have heard of guys making them work with aftermarket head units but the time it takes to get it to work is wasted when a aftermarket amp is better for the system that most guys/gals install.

[BlownPony]

Nope that kit wont work in my car...it had the ''primo'' sound in it but i took the amp out and cut the wires off it...so i trial and errored it till i got all the speakers hooked up correctly and it sounds beastily....anyway thanks for everyone's help.