Chris Baxter

Hi All,
First, I am very logical and mechanically inclined, but I struggle with anything electrical, so please be patient.
I have a 1970 convertible and I can't figure out why the brake light on the pass (passenger) side won't go on.
Tail light and brake light both work on the driver side
Tail light works on the pass side, but brake light does not
Bulbs is good (because it works fine on the other side
I replaced the tail light socket.
I believe the brake light wire goes to the back of the car, to the driver side brake light, then over to the pass side light., correct? So the brake (no pun intended) would be between the two lights??
Tail light socket has 2 wires going to it. Does one wire to the socket control the tail light and the other wire control the brake light? How do I know which is which?
Any advise on what and how to check?

Chris Baxter

I disconnected the two wires going to the passenger taillight socket; they are Green and Brown. The brown seems to be the taillight wire and the green must be the brake light wire. If I did it correctly, I checked the brown wire going to the socket and it shows ~12V when the lights are turned on, and 0V when off. Checked the Green wire going to the socket, and stayed at 0V whether the lights are on or off and whether the brakes are pressed or not.

Dogmark

The brake light wire to the right side is dark green that should be hooked up to your tail lite socket. The other wire in tail like socket is brown that’s for your tail lights. You’re a thought that the brake light wire comes to the back of the car to the driver side and then over to the passenger side is incorrect. The turn signal and brake light circuit uses the same wires yellow on the left dark green on the right, Obviously, the turn signal and brake lights are brighter than the tail light if that’s not the case switch the wires

Dogmark

With no voltage to the green wire With the brake pedal depressed was The key on? If not, try it that way, and if it still doesn’t work, the green wire must be broken somewhere You’ll have to trace it to find the break. Good luck.

Peterbuilt

With the brake pedal pushed, check for good corrosion free connection at "N" at the harmonica connection.

If that's good, remove the driver's side sill plate and kick panel and check at the 12 point plug.

Chris Baxter

Thank you for the replies. Yes, the brake light wire is the dark green one. I've pulled the driver door kick panel and see all the wires running to the front of the car. I will follow under the dash and see if something got disconnected.
Will try and measure the Voltage with the key on and the brake pressed in, just have to wait for my wife to help

BTW - the just checked the blinkers and the both the front and back passenger side blinkers do not work.

Chris Baxter

thank you for the chart, very helpful!!

Chris Baxter

There is a loose connection somewhere around the 12 point connector under the dash, because I wiggled stuff around and now it works!!
Thanks for all the help!!