what does GY/BU mean????? electrical

[RG5384]

okay, well i am bound and determined to figure out how to hook that temp sensor up, so i'm hopelessly trying to figure that #*#* diagram out. I THINK the wire i need to tap into is a wire that is labeled GY/BU, but what does that mean in real word terms? i'm guessing gray and blue? The wire i'm trying to tap into is the wire that the dimmer switch/potmeter controls, so that my temp sensor will be illuminated at night. If anyone wants to look at it for themselves it is on page 22 on electrical diagram index for a 1983 300SD, under instrument cluster lighting. Would my existing wiring be able to handle the added current draw of the addtional lamp? Thanks in advance
Ryan

[RG5384]

ok, nevermind. there is a help index just waiting for an idiot like myself to use, i was correct in my assumption that GY was gray and BU was blue. Now the only question i have is where would the best place to tap into the dimmer switch be? i'm fairly certain it can handle it b/c my car doesn't have heated seat switches and it shows those on there, so if it could handle the added draw of two more lights i'm sure it can handle one. any suggestions on that one? thanks again
Ryan

[leathermang]

I love it when someone answers their own question....
You can't assume on the colors , I have seen crazy combos used,,, you must find their ' legend' to determine what they mean by GY or anything else....
Aren't you the guy that took apart then entire dash,,,, would have thought you would have all those wire colors memorized.... LOL.....

[Billybob]

Yeah, gray and blue seem right, all your instrument cluster lights are controlled by the potentiometer but I seem to remember reading something about that control being indirect. I haven’t checked, but there may be an integrated circuit or its' module the pot is connected to, the dash lights are provided their voltage from the IC/module in direct proportion to the adjustment of the pot. If that is in fact the arrangement then you could pull your instrument cluster and follow the wires from the cluster lighting back to their source as there are numerous lights they all should converge somewhere. At that convergence point you may find an unused extra connection or some other attachment point i. e. a solder pad or the like. If not then a parallel tap into a lead from a cluster light should have a minimal effect as the bulb that illuminates the LCD is very low power and will have a very small current draw, but to be safe if you use the parallel tap scheme pick the cluster lamp that will have least overall effect, like one to the side rather than the overhead gage lights.
Good work Ryan, just a tip, the flow of electricity is similar to the flow of a liquid. Electrons are the water and the insulated wire is the pipe. Switches are like valves. Schematics are often easier to decipher if you eliminate those portions that do not make direct connections to the components you are working on, if you can segregate a portion of the circuit it is sometimes easier to understand what’s happening or supposed to be happening.