Can some one please help me!! I'm trying to put in a Pineer ph2900 head unit into my 1990 LX I'm sure all the wires are right, it powers on and recieves stations but no sound!! Is there some sort of stock amp that needs bypassed? PLease help!

 

probably. Is there a octagonal shaped box with a bunch of holes in it under the radio? Sometimes it is under the passenger seat....

If it is under the radio, there are two hrns's that go to the amp. Follow one that will go up and will have a black 8 pin hrns up behind the glove box. Unplug that hrns, get a standard ford 70-1770 radio hrns(if you didn't already) and use this new hrns as your speaker hrns and you have bypassed the amp.

I point to the exact same hrns onpage 2 of my cardomain page, it is just in a different location on a 94.