I've just about all the wiring under control on my 66 chevelle. One thing left is the reverse lights. All turn signals, park lights, front and rear work but I haven't got to the reverse lights. Just under the dash to the right side of the column I have a pair of green wires that are cut and a single I think yellow and I think grey or black. Could either of these be the reverse lights? Also I was thinking that the switch for the reverse lights on a manual transmission would have some sort of internal switch rather than linking something up to the linkage. However I don't see anything on the transmission. Should there be something there? Should I just rig something up with a normally open switch or do they make a part?

Don't know about a 66 but I have a 65 diagram that shows dark green FROM the back up light switch and black/light green feeding the switch.

Hey Johnny,
I hooked up a Hurst backup light switch in my '69 (eBay $20.00)--it is like the E brake interior light switch (I have Hurst shifter with a Muncie handle). It's a physical switch that attaches to the tranny (the bracket is a little cheap, so I reinforced it). When you go into reverse, the shifter depresses the switch and makes the contact.
Paul

Green wires - backup
grey/yellow - radio , grey is dash lights and yellow is radio power.

Johnny the light green and dark green wires are indeed the backup wires. They would normally plug into the firewall by means of a socket surrounded by a gromet that holds them to the firewall. From there another harness plugged into the socket and proceeded down to the transmission where a bracket that held the switch was located. From the switch a small rod hooked onto the reverse shift rod that actuated the switch when you shifted to reverse. Looking from the front of the car you should see about a 3/4 inch hole just to the left of the "hump" where your master cylinder mounts. They do sell a remanufactured switch, bracket and rod but it is somewhat pricey.

excellent guys thanks for all the info. almost forgot about the ebrake interior light. actually not almost I did forget. did 66 have an indicator light for the ebrake?