This has been going on for a while now, but it didn't do it right away when I switched over to the alternator system with the regulator built in in my 69 chevy. The engine is a complete tpi system. Same alternator and all. Whenever I shift gears, my radio shuts off and comes right back on. When I'm cruising along, it doesnt do it at all, even if i was to slam on the brakes or something like that. When I push my clutch in at idleing, the headlights get brighter. It will even do it when i shift without the clutch. and no matter what i do to it at a standstill the radio never shuts off. Its only when I'm moving in gears 1-3 even 4 sometimes, never 5. And every so often I will see a large static discharge around my shifter and shifter boot- I thought my truck was gunna catch fire one night. And then i seen it again and figured it was static. Its a really weird situation goin on. And its bothering me even more now that I just installed my pioneer 7 inch touchscreen. Any thoughts you guys have would be greatly appreciated.

clean your present grounds and add more grounds from your cylinder heads to the firewall and also check(clean well) your cab to frame grounds// ALOT of weird electrical problems are due to poor grounds, just because a ground wire is present doesn't mean you have a good ground cleaning shiney metal to shiney metal is the only way i know of to assure a good ground

things would be great if I ACTUALLY HAD A GROUND CABLE GOING FROM THE ENGINE TO THE CHASSIS AND BODY! The g force and engine movement while shifting was causing my ground "connection" to go nuts.

well if theres that much torque movement you might want to look into a torque limiting strap or chain for better performance

no theres not that much torque, its just that when you dont have ANY grounds at all going to the body and you are relying on your exhaust or something like that for your engine to chassis bond, it becomes alot of movement. The engine does move the truck side to side pretty hard. I'm using some custom polyurethane engine mounts.

Go to NAPA and get a ground strap set and put it on, that will probably cure your problem.

I had the exact same problem on my 68 when I was daily driving it. I worked 3rd shift, and if I bumped the shifter just righton my way to work, my headlights would freak out. I put a heavy ground strap from the cylinder head to the firewall, and that was it. No problems since.

A spool of 10 gauge wire also makes for good grounds. You can never have too many grounds.... within reason.