Looks like there are two wires to the sensor. One comes from the ignition switch, and one goes to the light on the dash. There are two things you can do. One, is using your voltmeter, turn on the ignition key and see if the one wire you have has 12 V when you do that. If not, that’s the wire that goes to the dash light. Somewhere in that loom where that one wires coming out is a likely red wire That is the 12 V source from the ignition switch. Or, you can crawl under the dash and find the wire that goes to the warning light. Then you can see if you have continuity between that wire and the one wire you have. If you do, if you found the wire that goes from the switch to the light.
If you’re unable to find a 12 V source in that loom, and it would be highly unlikely if it wasn’t there, you can always route a new wire to it that has 12 V at run position of ignition. Good luck.
Hello Mcmahst, thank you so much for this information. It will be a big time saver. When the wires burned in the loom it has been a nightmare separating the wires to trace the warning light wire. Thanks again!