I'm having an electrical problem with my dash board. I have a 77 Bronco with a Centech wiring harness. When I turn on my turn signals I get a small pulsing drop in power across my gauges and radio power line. I also see the same thing when I put on the brakes. I see a minor drop in voltage at the radio power line from ~13.5 volts to ~12.3 volts when the turn signals or brakes are on. I have a new 100 amp (single wire) Alternator installed that puts out 14.5 volts at the battery no matter whats running. I've checked grounds and they seem to be OK. Is it a problem to have multiple ground lines all connected to the same ground? Anybody got any thoughts?