[440roadrunner]

You did replace the socket, is that correct?

Do both tail light filments work?

Do both brake lights work? (Sorry, reread your post)

This is most likely the turn signal switch itself.

Somewhere, and I've forgotten where, there is an inline connector in the cable feed from front to rear. I think it's down in the left kick panel to the left of the dash. (I'ts been a long long time!!)

What you need to do is get a test lamp in the harness, and determine if it's in the turn signal switch, or the harness. I'll try and look up some test points

One thing you can do is this:

Get a test lamp, and get into the connector coming out of the column where the turn signal switch hooks up. You should have FOUR wires coming out of the connector which (can) flash, plus one for the flasher coming in. That is, let's say you turn on the left turn, and it is working. You should have a total of THREE wires at that connector which flash

One is the flasher unit feeding in "flash" power

One is the output to the left front

One is the output to the left rear.

Now try the same thing on the rear, and veryify that you have this at that connector. If not, you have a bad turn sig. switch. If you do have these three, then the trouble is the wiring or connectors going to the rear


According to my '70 manual, the RR wire at the socket is brown, the left one is green, and the tail is black

These go to a six pin connector up front somewhere, coming up under the left door kick plate

This six pin connector goes through the harness to the turn signal switch connector under the column.

Starting from the "pointed end" the connections shown are follows:

White
Brown--should be right rear turn/ brake
Green--should be left rear turn /brake
Red--incoming flashing power from flasher
Pink
Tan--feeds right front turn
Green--feeds left front turn
black