Wiring info steering column

[ed455]

I'm converting my 66 C10 to a mid-70's tilt column. It's the one WITHOUT the key switch on the column. I need help converting the turn signal/emergency flasher and horn wiring. Does anyone have a mid-70's cab wiring diagram they can send me in a picture file. I have the 66 diagram and can do the conversion from there. OR can someone tell me what colors do what on the ribbon wiring harness (8 wires).

[Slonaker]

As far as I know, all 73-87 trucks have the ignition switch on the column. Most, if not all, GM passenger cars went to a column mounted switch around '68. That may explain why no one has responded to your question in the 73-87 forum.

Slonaker

[ed455]

Yeah, that has occurred to me. The turnsignal wiring is the main thing. I have figured out a lot of it with my multimeter. There is one extra wire however.

Green and yellow - the rear turn signals
dark blue and light blue - the front turn signals
white - the brake light switch
black - horn ground
purple - 12v in
Brown - ???

These are similar to the wires on the '66. However the purple wire on the 75 column is pink on the 66 and the blues and greens are quite different shades. The extra wire that the 66 column didn't have is the brown wire. My guess is that it has to do with brake lights as brown is the brake light color on most chevys, but on the 66 the brown wire only goes to the key switch (although it is attached to the "always hot" post). I'm rewiring the truck, but will use the same basic wiring diagram.

Since the original layout is staying the same and the brown brake light wiring bypasses the column completely, my guess is that I can cap off the brown and ignore it. That makes the BIG presumption that the brown wire is indeed brake lights.

If someone can consult a wiring diagram and either scan and send it to me or just trace the brown wire on the diagram that is in the ribbon of wires with the rest of the signal lights, it would be greatly appreciated.
Thanks in advance.
Ed