Hello. Seeking helpful advice on lighting issues. Yesterday when I had to move my 72 I immediately noticed that my instrument cluster lights were out and the rear lights were out when I put on headlights. The brake lights do go on when pressing brakes. I checked fuse box and all the fuses looked good. Replaced the ones for brake lights and instrument cluster and no change. The signals work. Any suggestions on what to check next.

Thanks,

Andrew

 

The tail lights and brake/turn signal lights use different filaments in the same 1157 bulbs. The circuits and fuses are completely separate. The instrument panel illumination lights and tail/parking lights ARE on the same circuit and are powered by the same fuse. Review the wiring diagram in your Chassis Service Manual and use a test light to test for power at each connector in that circuit.

 

Seems like you have a bad ground in the system. Check all your ground locations for your lighting system.

 

Thanks for the notes. One clarification, could the light switch you pull to turn on headlights and rear lights be broken? When I turned dimmer there is no response for instrument cluster. Maybe parts of that switch are bad. I do have a spare headlight switch in my box of extra parts. Figured I would ask first before I remove that switch. Figuring if gauges are not lit and rear lights are out perhaps the switch may be common link. I will check connections as well

 

The rheostat that dims the panel lights does go bad. I has nothing to do with the tail lights. Also, there is a separate 4A fuse that only powers the panel lights. Check that one before pulling the switch.

 

 

Did u ever figure out what was causing ur light problem?