I'm a little confused, but here's my shot at this..........
NOTHING at the cluster terminals labeled for gauges gets power. That is, oil, temp, fuel. These are SENDER wires, and the senders control that line to ground
In other words the "circuit path" is
Coming off the IGN switch IGN1 terminal or "ignition run" branches off and feeds the instrument panel connector.
So you have "ignition run"...........cluster connector..........IVR.......to the gauges.........through each gauge........out the cluster connector on the sender wires...........off to the senders........through the senders...........to ground.
Those diagrams aren't that great. You can download a factory shop manual for free, here's our thread:
http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617
The 67 manuals actually coming from "MyMopar
So if you download the "67Dart / Charger / Coronet" and use the Coronet diagram..........
http://www.mymopar.com/index.php?pid=31
http://www.mymopar.com/downloads/servicemanuals/1967_Dart_Coronet_Charger_Service_Manual.zip
Below is page 312 plus or minus. The "dash" page numbers don't work the way these have been posted
Notice that you can follow where the cluster stuff goes just by following the pc board traces on the back.
(I posted that wrong it's a Dart cluster, but illustrates how they "look")
Make sure to repair the loose broken connector pins, check continuity and solder the IVR socket contacts, replace the IVR with a good one and tighten the gauge stud nuts
Now, in the second from bottom, find IGN1. This is "ignition run" and is hot ONLY in "run." This is what supplies the regulator / ignition in the engine bay, and splits off to feed warning lights and the IVR power for the gauges
On the second from bottom diagram, find the circular PC board connector, and wire G5-18DBL. This is circuit G5 and is a no 18 wire, Dark BLue That wire eventually ends up branching into the IGN1 "run" wire
Look at 4th from the bottom, top right, directly under the heater switch. There's a splice there, and "G5" is coming in off the right hand of the page. The wire feeding off to the right J2-16DBL off the page, comes back in from the left of the diagram 2nd from bottom. This is easier in the shop manuals because I've had to split the diagrams. Anyhow "J2" is coming off IGN1 of the ignition switch.
Hope that isn't terribly confusing.