Topic: Electric Question--High Beam Indicator Light

[Skyway65]

Attention Midlife—I have a question for you…or anyone else who can figure this out...

I’m having an issue with the high beam indicator light in my ’65 with the standard gauge cluster.

When the headlights are on the red indicator light will function properly-it goes on and off as you depress the switch on the floor. 

The problem is when the headlights are turned off the red indicator light continues to glow red, although it is a bit dimmer than it was when the high beams were actually on. 

Any ideas what’s going on here? TIA

[CharlesTurner]

Have to ask the obvious... did you replace the headlight switch and dimmer switch or are these original parts?  Any other gauge or lighting issues with the instrument panel?  Could be a ground problem, did you use the original star washer when screwing the main wire harness ground to the dash support bracket behind the cluster?

[Skyway65]

Hi Charles-- The light switch is original, the dimmer switch is a repro, the ground wires appear to all be tight-can't recall about the original star washer specifically but I did use all the original wiring.  Everything worked when the car was taken apart.  All other electric systems on the car are working properly.  The only issue is the red high beam light...Thanks--Gary

[midlife]

Wow...never heard this one before!  You have two leads to worry about: the green/black wire (signal to the high beams), and ground (black wire).  On a 64.5, I believe the ground is the case.  If the light still is dim, then you either have some voltage on the green/black wire or some sort of a feedback through the ground from some other system.  It could be that the dimmer switch is not good (sending some voltage from power in to the highbeams when it shouldn't).

You can test the system by removing the bulb out of the dash cluster and ground the bulb socket housing to a good ground.  If it still lights up as described, the ground is not the issue.  I'd then measure the voltage at the bulb tip to see what's going on.

[CharlesTurner]

Seen bad turn signal switches do weird things like this also...

[Skyway65]

Thanks for the ideas Randy--later this week I hope to get back at it.  Based on what you and Charles have said it's looking like the new, repro, dimmer switch is the place to begin.  It is the only piece of the puzzle that has been "switched" from original. 

[Skyway65]

Update on the high beam mystery.  After many hours of tracing, trial and error and some extra support from Randy, aka Midlife, the problem was traced back to the temp gauge.  It was shorted out in the metal slot that holds it into the metal gauge cluster.  This caused the entire metal case to be "hot."  Maybe this can help someone else in the future.  Thanks again Randy.