I think it's your wiring....if you can get yourself and your car down to the Port Credit area tomorrow (Wednesday) evening PM me....I will check it out for you and show you how to diagnose problems like this one.

LMK

 

i had a 4002MTX thunder. same problem. turned out the factory solders for the power remote and ground were to big and when given enough power would short out very rappidly and sometimes it would work just fine. i pulled the pannel off and fixed it no problem with my desoldering gun. 2nd mtx thunder i have repaired for the same problem.

 

^^^same thing happened to my mtx amp it would turn on and off as it pleased

 

try these

a) disconnect the speaker wires from the amp, does it turn on?

b) check your remote wire from the deck

c) check your fuses!

d) double check your ground