electrical issue

[fran kelly]

Issue with brake lights and directionals in my 1964 356C. When I brake without the directionals the brake lights are fine; when I use directionals without brakes there is no proplem. But when I signal to turn left or right and have the brakes on, the opposite directional light also flashes somewhat. Years ago the directional arm and wiring was replaced due to spring issues. Not at all sure why the directional lights are both blinking when brake and directionals are both on?
Thanks,
Fran Kelly

[David Jones]

Probably a ground problem Fran. Check the ground wires on both rear lights. You could also add temporary ground wires using croc clip for testing.

[fran kelly]

Thanks David. I did clean the ground on driver side but I'm not sure there is a ground on passenger side? I have Bursch exhaust so it is somewhat hard to get up in there. Additional comments?

[David Jones]

Try a separate grounding wire. Take lens covers off and connect to the metal frame.

[Martin Benade]

You could even temporarily ground it to the bezel screw on the outside

[David Jones]

I would use the generator case as my choice for best ground.

[Jim Liberty]

As a matter of course, I ground every electrical device separately. I check continuity with a tester also. .............Jim.

[Al Zim]

If you have a 356 sold in Europe the tail lights will be wired differently then those sold in the rest of the world. This may perpetuate your situation.

[Greg Bryan]

Fran - did you get your problem resolved?
I think the advice you have received regarding grounds is a good place to start. My recollection is that the left side rear lamp assembly has an actual ground wire that terminates at one of the fixing studs. On the right, there is a piece of sheet metal strap spot welded to the body and attached to one of the lamp assembly studs that is prone to breaking off, so that's a good place to check.
Also, David had a good idea to use a jumper wire with alligator clips to install temporary grounds for troubleshooting.
Good luck!
Greg

[Bruce Smith]

Fran - I don't doubt that it's a grounding problem. But also check to see if you have any lamps wired backward (+ for -). Although a lamp may be working, the ground in that circuit may be upset. From intuition, you may think that this would be a short, but not necessarily.

[Kevin Wills]

Fran, do you have a third brake light wired in? If so, how did you wire that in?