Robsinno

Need some help with figuring out why the hot wires (Red and Orange) on the headlight switch for my 68 Firebird are only supplying 10.5 volts to the switch. The issue I have is with dim dash gauge lights. I have already replaced the headlight switch and checked grounds. Car was rewired with a Painless wiring harness about 15 years ago. I started having this problem about 5 years ago. It seems to have gotten progressively worse since then. Thanks in advance.

Robsinno

I found the problem about an hour after posting this thread. It was the main ground wire from the battery to the frame. I started checking grounds from the battery first and noticed that the frame had some pretty heavy surface rust where the ground wire was bolted to it. So I disconnected the ground and took a wire wheel to the frame until I saw shiny bare metal at the ground connection location. Bolted the ground wire back to the frame, and rechecked the voltage coming into the switch. The meter read 12.07 volts at both hot wires and 11.35 volts at the wire going to the gauge lights. Gauge lights are bright again!