Weird dash blinker light problem

[Maverick402]

For some reason the left blinker light in the speedo/tach cluster only works if i have had the headlights on for at least 5 minutes. The right blinker and brights lights work fine. The Brake light doesnt work either, although it has worked one night. I made sure all the connections on the printed circuit were in there good when i put in the connector. Anybody have any ideas? thanks.

 

[wishuwerehere82]

That sounds like a directional switch contact problem in the steering column. It disables the brake light when the switch is on and the turning signal is flashing.

Pete.

 

[Maverick402]

But why does the left blinker light only work after the headlights have been on for a little while? Right blinker light works fine

 

[wishuwerehere82]

The lights are on long enough to arc through the oxidation on the switch contact on the left side of the switch. Once it arcs, the contact has melted copper exposed on the contact pad, and will work for a little while longer.Copper will oxidize very fast and the contacts are plated with palladium or tungsten for that reason. Once the contacts start pitting they will continue to give you problems.

Happy Independance Day!!

 

[Maverick402]

Well the blinkers on the outside of the car work fine. Its just the left blinker light in the speedo tach cluster. The blinker switch would effect that?

 

[wishuwerehere82]

Sorry.

I completely mis-understood.

 

[Enigma]

I'm looking at the electrical schematic for an 80 vette and the two circuits are completely separate from each other. The head lights are controlled from the light switch and the turn signal lamps are controlled by the hazard/direction switch assembly. They don't even come from a common fuse connection.

I can send you the schematics for the circuits in question if you don't already have them.

It may be something in the wiring harness or maybe a bad ground point.

The left/right dash indicator ground is on the left pillar above the courtsey light.

Good luck

Enigma