I seem to have the same problem too! I've got a high/low converter wired to the stock 6CD changer and that is wired to an MTX amp and subs. I took out the factory sub, but left the factory amp. They worked aright for the first few days, then no bass. I've felt my MTX amp (I installed it where the factory sub used to be) and it's pretty darn hot. I'm thinking it's because the new mexico sun is cookng the inside of my X. I know the sub amp is getting power because the light comes on, and the subs move a little, but not enough to make bass.
Does high heat cause audio equipmentto semi-fail like this?
Clarkkent, the factry amp is just to the left of the factory sub behind the panel. BTW, it's a pain in the butt to get to; you have to remove the entire panel to really do anything to it. (At least that's how it is on my 02.