more electrical diagram help needed please

[RG5384]

i know i've been asking for this type of thing, and beleive me, if i knew how, i would much rather look it up myself. I would greatly, greatly appreciate it if someone could help me out with this. The dilemma is the following, i have a temp sensor out of an 85 300SD that i am retro-fitting into my 83 300SD. I know which wires go where on the sensor, however, i need to know where i can tap into a 12volt power wire, a lighting wire(off of the potmeter dimmer switch, for the lighting of the switch). I know where i can find the ground wire(duh), and running the sensor line is easy as cake. I appreciate all your help, i really which i knew how to read electrical diagram's, and i dont want to do a "mickey mouse" installation. If i wanted it to look/work cheap i would have boughten a 10 dollar aftermarket one! plus, i wouln'dt have gotten the added neatness of it reading in celcius.......lol
Ryan