The headlights and front parking lamps work. The front turn signals do not. The rear light harnesses have power but they will not light up. I cut the second wire and place it on metal in the trunk and the lights turn on. SO, where is the ground that I am missing in the wiring harness? Or is the ground not in the harness? The second wire on the harness appears to run back to the turnsignal switch under the dash. I have power to the license plate lamp but this runs form the main light switch connector. I checkd the connections all the way back to the dash and everything seems fine. The back up lights are not connected. Could lack of a connection interupt the circuit and prevent the lights from working?

 

Fixed the problem. The light sockets were bad and so was the blonker switch. The tail lights ground themselves when placed in the lamp housing, hence the two metal contacts on the upper ring of the light socket. The car has a tilt steering wheel setup and when I took the switch apart all the contacts were worn badly and there was a lot of play. The brake light switch feeds through the blinker switch. after replacing the switch (purchased from OPGI in Seal Beach, CA) and adjusting per the '64 service manual, the tail lights work great. If anyone needs help in the future please let me know. I have the wiring schematics for the '64, and '65-'67 cutlass.

 

Glad you got it fixed - I seemed to have missed this one...

 

I have a 67 f-85 my tail lights are always on. no brake lights and when I pull the light switch to get the courtesy lights the tail lights go out. I could really use a set of wiring schematics.

 

I think I have a schematic but it is at home. If it is like the '64 and '65, all the taillight controls (running lights, brake, blinkers) go through the blinker switch. Is this a new problem? I will send the diagram on Monday. PM me with your email address.

 

I had this exact same problem with my '67 Delta 88. Turned out that the underhood light power connector was connected to something other than what it should have been causing power from whatever that was to flow back through the underhood light and to the taillights, which are on the same circuit as the taillights.

After trying for a while to figure out what the problem was and failing, I started working on other things, including fixing the underhood light, which also didn't work. As soon as I disconnected its power connector, everything started working properly.

 

I've got the '67 service manual, so I scanned the wiring diagram for the Cutlass V-8, which I'm assuming you have. There's a different diagram for the L-6 engine. A link to download the diagram is below. It's available to anyone and should be active through 7 days from today.

I scanned it at an insanely high resolution, so the file is large (about 12 MB), but these diagrams have lots of tiny print. With the high resolution, you should be able to open the image in a photo viewing program, such as Windows Photo Viewer, zoom in, and everything should be clear and readable.

Let me know if you have any problems downloading or opening the file.

http://www.sendspace.com/file/x2pmqu