hi,i have a 1972 nova [factory tach/clock and gauge console v8]and am having the weirdest problem..seems the headlight switch dimmer also activates/brightens and dims the taillights-stop-running lights and side all side marker lights when the ignition is turned on..also the heater and console shifter lights come on also..this happens when the headlights are off....if you have the dash cluster lights dimmed all the way down and the ignition on it seems fine but when you brighten the dash lights then the brake/side markers get progressively brighter....once you turn the headlights on and start the car all seems fine...the car was a basket case but looks like the underdash harness isnt cut up....i have tried to find all the grounds and the headlight switch is new[does the same as the old one]...flashers work fine-turn signals seem ok.....the dash carrier is out...its a needle in a haystack but any info/help would be much appreciated...thanks,mike c

Welcome to Team Nova, the problem sounds like a bad ground. Check that all the harness grounds at the front and rear of car are clean and tight. The under dash harness may have several ground points and the head lamp switch needs to be grounded for it to function properly. Since it is mounted in plastic there is a wire or strap that goes between the switch and the dash that grounds to the metal body. If you have a GM service manual there is a good illustration of it on page 12-12.