ok putting in an alpine head, all stock wiring

wiring harness i bought fits perfect. (metra harness for 92+)

my car is a 1989 GTU

are the rears amp driven? theres nothing in the towers, just wire + speakers (crappy kenwoods for now)

the rears crack and fuzz and sound like crap. sounds like they are getting too much power... cant find an amp. does the dash amp run the fronts and rears? can i just unplug it?

 

I know 1st gens had amps for the rears, and I've only encountered two coupe FC's here at the shop and they didnt have an amp or it was already bypassed. I recommend running new wires straight to the speakers, this will alleviate the problem 100%, unless of course there is a problem with the speakers or the headunit. Just cut the rear wires in the aftermarket harness (green & green/black and purple and purple/black) and run new wires straight to the speakers from there. But before you do that, make sure the speakers are firmly plugged in and all the connections are properly connected. If everything is solid, then just run new wires.

 

^ agreed, the only way to go is running new wires to all your speakers, and you will be much happier in the end.

 

Unless you are running more than 50 watts RMS (not peak) into a channel the stock wiring is perfectly fine.

On your 89 GTU, does it have 4 inch rear speakers or 6 inch??? If there are 4 speakers, then it has an amp built into each speaker assembly. If it is 6 inch, the amp for the rear speakers is bolted under the headunit to the same metal assembly as the head unit. So if that is removed and the speakers sound like crap, chances are the speakers are OEM and blown/worn out 5 years ago.