I have a 97 GT Convertible. I still have the factory stereo with Mach sound. I hear a humming noise in speakers and a loud thunderous sound coming from the door speakers. It comes and goes. When engine is off I dont hear the humming noise but the thunder noise will come and go. Any Ideas ?

 

Turn down the radio all the way and rev your engine. If you get the same sound then you are in need of another grounding wire. You may want to check the noise reducers from your coil packs. If every thing is good then you more than likely have an ignition coil that the insulation has gone bad. Also check to see if your grounding wires have not gone bad (rusty or dirty) near the MACH amps/.

 

[sm=hail.gif]

 

thanks for the info, Would that also account for the loud, thunderous, door speaker noise as well ? It comes and goes.

 

[sm=hail.gif] +1

 

OK did what you said. I turned down radio all the way. Still hear the engine noise. Did you mean I need a new Battery Ground wire or Radio ground wire. WHere is the ground wire located for the mach amp ?