You want to check the resistance between the ignition side of the yellow wire and black wire. You don't have to touch the white wire. Once you find the resistance put the same value of resistors between the black wire and the non ignition switch side of the yellow wire. Solder up and seal it up and you are done. I'm not sure what wire colours are in comparison with your neutral, hot and data wires. It is a simple thing to do, but hard to get at in my car at least.