Electrical: Wiring help

[oldguy]

61 hawk. All the external lights work, however, when the right rear turn signal is on, the left backup light blinks??
Any hints where I should start looking?

[JohnM15]

Check the grounds at the light.

[radiotech]

Bulb and socket in the wrong hole???? It happens. Start with the easiest thing to correct and work back. Bad ground would be the second thing to check, a rusty or oxidized housing or socket could cause this problem. Make sure all grounds are tight and shiny!

[rockne10]

Back up light and turn signal are two distinct circuits. I would suspect a combination of a ground issue and possibility of two wires to rear harness being pinched somewhere.

[gordr]

That is exactly what would happen if you both a bad ground on the RH stop/tail socket, and had the LH stop/tail and BU lamp sockets in the wrong holes in the lamp housing. If that is the case, you should see the LH backup lamp blink if you signal a left turn.

Make sure that you have the right bulbs in the right sockets. Stop/tail should be #1157, although #1034 was used originally. Double-contact bulb with staggered bayonet pins. Backup should be #1156, single-contact, equal bayonet pins. There are some double-contact bulbs with equal bayonet pins out there, notably used in some six-volt Studebakers. One of them could do weird things if inserted in a single-contact socket. Also, you can file the odd pin off a staggered-pin bulb, and use it in a single-contact socket ( a CASO way to recycle a dual-filament bulb burned out on one filament, bridging the two base tips with solder).