What does this plug do?!?

Discussion in 'Mustang Sound & Shine All' started by SkittleTits, May 21, 2011.

  1. Hey guys, I am not sure what this extra plug is? Car is a 92 Mustang LX 5.0. No idea if it had premium sound or a factory amp. I installed a wiring harness for the black plug and gray plug but I do not get any sound. What do I have to do to make this work? Thanks!