clicking speakers with accelerator and reception
sounds like your picking up interference from your alternator. Try checking your main power supply line to your amp. I know i had the same problem with my stereo and it was because i bought a cheaper power feed wire, picked up a higher end one and the problem was gone.
Another thing, how do you have the wires ran? If you have the Power wire running along with the RCA and the Speaker wire, then that might be part of the issue. Perhaps it has always done this, and now that the copper is aging, it's getting worse?
it was installed at the beginning of summer or so, power wire down one side of cab, others on the other....ill snoop around tomorrow.....alternator is a possibility, ive got the lowest stock one and an efan



