'80 Z28 almost there...a few(hopefully minor) glitches

I'm having trouble getting the back up lights to work in my '80 camaro Z-28. Theres a diagram for them at
http://www.nastyz28.com/camaro/wire/78w-rear.jpg
. I dont know if it's a fuse or not but I'm pretty sure theres nothing connected to the back up switch, but I'm not sure which switch it is or where it could be found. If you know where it would be, or if I found it, what color wires hook up to the back up switch?
Also, my tach, oil pressure gauge, and gas gauge do not work after removing the instrument cluster and playing around a little bit with the wiring. Do they have any common power/ground sources that I should check? Does any of them have a separate fuse/switch/relay that I should check? If so, where would they be? Theres a diagrams of these on nastyz28.com, at
http://www.nastyz28.com/camaro/wire/78w-ip.jpg and
http://www.nastyz28.com/camaro/wire/78w-ip1.jpg but theres a big difference to me in the pictures with abbreviations of these switches/ relays/fuses and what it actually looks like in person.
I just need to figure out atleast the tachometer(because it's a stick), gas gauge (I'm too dumb to be able to tell by the mileage, and I know it worked when I bought the car), and the back up lights (so I can pass inspection) to get this baby on the road. Any help will be greatly appreciated.
I dont know if it helps, but there is a decent thickness orange wire coming through the firewall through a grommet that was definitely there from the factory, and its disconnected before it gets to wherever it needed to go in the engine compartment. I'm not sure where it goes once it gets inside the car, if you can help me figure out what it might be I can try and trace it.
There is also a gray .8 wire that comes from behind the fusebox the got cut somehow that I'm not sure what it is. The ends of these wires are easy to get to and I could test them if I knew what to do...
Thanks, Brian
If anyone here lives around Massachusetts I'm willing to exchange a full set of black Z-28 rims for help with the car or a trade or cash...let me know.
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The orange wire sounds familiar. I last played 12+ years ago with my '78. IIRC it should go the transmission. TH400 was on the drivers side rear half above the sump. There should be a connection around abouts for other transmissions.
HTH
--
Mitch - 1995 Z28 LT1 M6 terminal snipped-for-privacy@sand-hill.freeserve.co.uk
Lancashire England http://www.sand-hill.freeserve.co.uk/terminal_crazy /
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Just had another thought. I disconnected the linkage between the transmission and the steering column, the one that drives the PRNDL on the dash. IIRC I could rotate the ring behind the steering wheel and turn on the rear lights, so it could be controlled by that.
--
Mitch - 1995 Z28 LT1 M6 terminal snipped-for-privacy@sand-hill.freeserve.co.uk
Lancashire England http://www.sand-hill.freeserve.co.uk/terminal_crazy /
  Click to see the full signature.
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They probably still used the backdrive to the steering column switch in '80. There are some linkages from the ST-10 transmission going to an arm you can probably see on the firewall, coming off your steering shaft.
The backdrive provided both the backup lights and the business where the shifter must be in reverse to get the ignition switch to "lock" position. As well, if the car is locked, the lever is stuck in reverse. (Although if you reef on it enough, you can probably break something.)
Anyway, this is how it works on my '78 Trans Am with manual transmission. The backdrive linkage is often removed--it interferes with headers, for example. I also suspect that it's very hard to find, as the linkages were probably removed years ago, and now are in demand for 100-point restorations.

I don't know the answer, but you should be able to get a cheap used copy of the GM service manual. All the wiring diagrams will be in there, with colour codes and all. There is almost no way to troubleshoot the electrical system without the factory diagrams. The factory service manual is essential for anyone working on their own car.
....Ed
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it would be the same as the T/A right?
If so I have the diagrams etc........email me at rockinrotho at yahoo dot com

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