My 72 olds has this annoying problem with flickering lights. All the lights in the car flicker at low idle. If I put the light switch to parking than this sound that I will describe lessens. All lights on than the sound is back. The sound is a clicking sound under my dash. I replaced the alt. and voltage regulator thinking that was the problem with delco. No solution. Courtesy lights will also flicker if car is on. High idle than the lights will stop flickering. This is over 1000rpm. I tried adjusting the regulator to 13-15 volts but the closer to 13 and over I get the more they flicker. I appreciate your help even though I have a olds.