The original CJ-7 wiring harness is intact....after I cleaned up a bunch of monstrosities from the PO.
I've added seven of the Autometer Phantom II gauges to a custom Double D dash. I've added quick disconnect plugs for each of the gauges, which will help me remove/replace for future failures/upgrades. These connectors are made by Tyco Electronics (part numbers available upon request).
Although this looks like a mess of spaghetti, it's not. You can see the quick disconnects (black plugs) I've added to each gauge in this picture. I apologize for these pics, they're from a stupid iPhone. I'll straighten out, clean up, and zip tie up this mess when I'm done with the wiring.
I've only got two more gauges to go -- the Tach and the Speedo.
For example, here is a pic of the tachometer quick disconnect plug.
There's only four wires that go to the tach
1 = +12V Lighting (white)
2 = Ground (black)
3 = SIG to - side of coil (blue)
4 = +12V Switched/Ignition (red)
These four wires will come from the original Jeep's wiring harness (save for the blue coil wire, I just ran a blue one myself through the firewall to the coil) and I will solder pins that fit into the back of this plug to allow for the quick disconnect.
Reason I asks this is because I wasn't sure if the load of these three gauges (speedo, tach, and the GPS Speedometer Interface) would be too much for one switched 12V source. Looks like it's not. Now looking at the wiring diagram I have of a 1985 CJ-7, it looks like there are a lot of "splices" that route 12V power to various components.
I'm using 16 AWG for all the new wiring and I have crimped, soldered, and heat shrunk all the connections up to this point. Also, I'm adding a 4A, 3AG inline fuse for every gauge on the 12V Switched input. I would rather crimp, solder, and heat shrink all the connections and not have any open 12V sources hanging out there...too easy to short something out otherwise.
It looks like splicing is the best option at this point. All your input is greatly appreciated!
P.S. Ignore those wire nuts. They are temporary to test the 12V source for the LED lights behind the gauges. Those will definitely be removed prior to buttoning this up!