cutting back of dash

cosgig said
Are you sure that the proper hookup isn't there already?? The hole should be the same between the light and the guage, and it must have a 2 post system that is run through the circuit board! I don't think the circuit board would change unless it's not the same year guage and car! The change would be in the sending unit, which sends a signal to either the guage or the light, with a different sending unit for each option!! Correct me if I'm wrong, but I think that's the way they're coordinated!!

Where a bulb socket mounts is totally different from where a instrument mounts. OEM instruments operate on reduced voltage too. All bulbs operate on 12 volts including that oil lamp.
If what this owner wants to do can be done, it will require butchering the circuit board and adding wires to replace some copper traces, and wires to add the new connections. The only thing that doesn't change is the gray wire from under dash harness to the sender.