Audio Systems: Car Stereo in 72 GTO turns on/off at will, pioneer cd changer, fuse block

Question
Hi:
I have an aftermarket Pioneer CD changer with 4 speakers installed in a '72 GTO. It works fine as long as I am parked in the driveway. Once I engage in reverse or drive, after 15 seconds it will turn itself completely off, then on again. It continues to do this while I drive. The on/off does not correspond to bumps. With the car running but parked and the stereo on I have pushed up and down on the bumper but cannot get the stereo to fail. Also I have done the following:
a) Checked ground.
b) Tested wire from Battery to firewall
c) tested wire from fuse panel to deck
d) checked all connections for correctness and tightness of fit,(all connections soldered and tight.)
e) pushed faceplate while driving. (It has a detachable faceplate. Thought it might be loose.)
f)pulled, tapped and moved every wire and connection while the stereo is on.
All to no avail.
What's up? I contacted the shop that did the installation and they blame the deck.The deck is out of warranty and I cannot afford another one right now.
Can variability of power cause these symptoms?
Any other ideas?
Thanks in advance!
Mike

Answer
Mike,

 ok you have done some pretty good troubleshooting, and trust me i understand where you are coming from with buying a new deck .. so here is a cheap way to really put a definant of if your deck is bad or not .. since you are working with an older car * good choice by the way i have i'm working a deal of 71' 442* i would recommend running a complete new wire system .. meaning instead of going through your fuse block run everything direct using inline fuses.. this means .. solid connection between a fuse from the batt to the head unit .. solid ground to the head unit .. you will need the 12volt ignition wire that kicks the unit on which can be ran from the fuse block or from the direct source eitherway.. then all the speaker wires will be run with new wire if they are not already.. its pretty much installing the system without using anything the car has besides the ground *which comes from the body or frame and the ignition wire* nothing on the car should be used or reused besides those .. try this .. it will cost about 10 bucks at the most for the fuse and some wire .. if this fails .. then its more than likly the head unit... hope this helps you out if you need anything else let me know

thanks