I'm installing a cheap Sunpro Mechanical Oil Pressure Gauge in my 73 Charger. Since it had only the Standard Gauge Cluster originally. But I'm also still using my original Oil Pressure switch tied in with this new Sunpro mechanical gauge using a brass tee. That's done. I mounted the gauge in the center of the dash under heater box using exsisting screws. It looks perfectly centered in the interior, viewable, and secured tight out of the way of anything. Now hooking up the wires for the illumination light is difficult for me since I'm not good at electrical. I did fully redo the interior and went through the wiring harness piece by piece and made sure all exterior and interior lights were working before I go to install the engine. Do I want to tie in the illumination for the gauge with the dimmer switch or just power it up at one brightness or can I? Where is a good place to plug in the positive? It would be nice if it would work in conjunction with the dimmer switch but if it's easier to do without then I'll do that.

Just tie it into the dash light wiring, then it will work on the dimmer.

On an e-body there is atleast one orange wire under the dash that the console and ashtray light plug into. Usually there is an open terminal in this connector for another bullet connector.

Run the 12v wire for the gauge lights from the dash light fuse. It gets it's power from the dash dimmer part of the headlight switch.