Need Help, Electrical Gurus

[2drSE-i]

As some of you may know, i am building a UV gauge setup. Now, i want to be sure that im doing all the wiring correctly before i go to install it into the car. What i plan to do is build a gauge test harness.

Heres what i have: I bought a DC 12v blacklight with a cigarrette adapter and an AC/DC converter, which i have successfully used to prepare my gauges. Now im in the install phase.

Im going to the junkyard today to grab the gauge harness out of the dash of a car. Thats the three plugs that go into the back of the gauge cluster.

Heres a picture of what im dealing with.

and the pinouts.


Alright now im not sure if im gonna get the dimmer circuit wired, but here are my plans for now. Im chopping the cigarrette adapter off the end of the blacklight wiring, and im going to use that as my positive source. i plan to solder the blacklight into where the stock gauge light goes.

Unused wires: A1, A2, A3, A9, B2, B5, B6, B7, C1, C2, C3, C4, C6, C7
These are the wires that go to the dimmer switch circuit, gauge input, and unused warning lights.
Ground wires: A8, B8, C5
Now two of these are grounds for things im not wiring, but im putting them in just in case.
Positive wires are everything else.

Heres my question for the electrical gurus. Is this gonna work? An even better question is is this gonna work without the dimmer switch? i dont think it will be too difficult to get the dimmer switch wired if its necessary, but im just curious.

Oh and for those wondering why im wiring the warning lights its just to make sure that they are working. I pulled this cluster out of a junkyard car and want to be sure that they are working. Im also working with some LEDs.

[2oodoor]

ok , that was a lot to take in so I am trying not to make things more complicated than they are..
How sophisticated was the power supply for the blacklight? some of those have controller circuts and it is 12 volts dc REGULATED, anyway...so if the light works just on battery voltage, I dont think it will work with a pot switch for varying resistance on the ground side (which is what the dimmer is) I would not even use the dimmer, disable it. The only way to dim the tube style light is to shade it with something and yes that could be done with a cigar tube or something that could turn it.. ???I would have to see the light you have.

It is confusing when you say dimmer switch because some people call the high beam switch on the mulitfunction stem the dimmer.

[2oodoor]

You need the schematic for the cluster . You should not tie all of those into the same ground because the guages and some warning lights work from the devices own resistance to ground. I think the dimmer is just a junction ground on one terminal. Just because the circuit is identifed with ground or negative polarity does not mean you can hook it to ground and expect it to function.For your blacklights, backlights, yes you can but not the warning lights and guages.

[2drSE-i]

ok so your saying that i cant tie the blacklight in with the dimmer switch (the dimmer im speaking of is the switch over by the headlight retractor and rear defrost switches) because it may not work.
You are also saying that i cant ground all three circuits into the same ground, which makes alot of sense...i just need to figure out what i can use inside my house as a ground.
I dont need to dim the blacklight, i just want the rest of the lights to work off the the dimmer.
By the by, i do have the wiring diagram for the gauge assembly, i just cant make apples or oranges out of the damn thing haha.
I think what i may wind up doing is wiring it all up and hoping to god it works....

[2oodoor]

I think your model is going to be more work than the actual project.
The ground in your house, huh? you just use the negative pole output from your dc adapter.
The dimmer , you can use it with the regular incandescent lights, and maybe even a led panel depending on how it is made. But the other thing I would say no, the dimmer is a rheostat kind of thing that varies the resistance on the ground or negative side. There may not even be positive or hot coming out of it, just a controled negative. I do not have access to the schematic right this minute or I would clarify that. Maybe tommorrow.
You are better off using a hot lead from the headlight switch for the black light, or tap into the fuse that is energized by the headlight switch for your dash lights. It is only hot when the lights are on.

[2drSE-i]

I think your model is going to be more work than the actual project.
The ground in your house, huh? you just use the negative pole output from your dc adapter.
The dimmer , you can use it with the regular incandescent lights, and maybe even a led panel depending on how it is made. But the other thing I would say no, the dimmer is a rheostat kind of thing that varies the resistance on the ground or negative side. There may not even be positive or hot coming out of it, just a controled negative. I do not have access to the schematic right this minute or I would clarify that. Maybe tommorrow.
You are better off using a hot lead from the headlight switch for the black light, or tap into the fuse that is energized by the headlight switch for your dash lights. It is only hot when the lights are on.

like i said, i think ill just slap it together (not literally, im taking my sweet ass time with this project) and wire the blacklight differently. i forgot that the dimmer switches in our cars operate off of the ground. i guess it really makes sense because if they used the positive it would burn stuff up.

Im thinking really hard on something that is powered close to the gauge cluster but not dimmed.