I am in the middle of replacing my door speakers and cant seem to find the amplifiers so that I can bypass them. (I tried posting this in the audio section but it is seldom visited). Thanks

 

run new wires

 

it is behind the drivers front little 4in speaker by the hood release

 

I'm unsure of any differences between S4s and S5s, but on both of my 91s, it was on the passenger side bolted to the dashboard frame.

The amp input and output harnesses can be unplugged from the amp and plugged into each other to bypass the amp. But, as Rob said, just run new wires.

 

Best of my recollection........ that amp is under the glove box, right beside your 3.5" dash speaker. You can disconnect the two wiring terminals going into it and plug them into one another (bypassed).