I just installed a Sony CDX-GT550UI stereo in my 71 Z. Unit works fine when the vehicle is not moving, but shuts off temporarily whenever the engine is under load, such as acceleration or going uphill. It comes back on when coasting or under no load.

Initially I had it wired to a circuit controlled by the ignition switch, but changed it to being wired directly to the positive terminal of the battery when I first encountered the problem.

Could the problem be a bad voltage regulator?

The voltage regulator appears to be very old and the alternator looks to be recently installed.

Start with your inline fuse and then your ground - they may look good to the eye but .................

I checked the voltage regulator. It is charging at about 15 volts at fast idle and up to about 17 at 2500 RPM. New regulator has been ordered! I,m guessing that the stereo hase some kind of circuit protection against excess voltage.

Probably explains the moisture (battery acid) by the vents on the battery after driving!

Just replaced the voltage regulator. Radio now works fine and no acid condensation on the battery case after driving.

GREEN

Just a thought but give that area on the inside of the right fender a good rinse with water. Most owners don't know that the gas from the battery can corrode just as quickly as the acid itself.

Thanks for the tip!

Apparently this has been a problem for a while before I bought the car as part of the battery tray has been eaten away and there is some corrosion on the firewall. Fortunately not too bad and looks to be easily cleaned up and protected.