Wiring in a new Rocker Switch

[Jeff95814]

I want to light the inside of my control panel and have a nifty little LED light strip, a new rocker switch that will fit the existing blank opening and have removed the control panel to access the wiring. This is where I'm needing the help of you knowledgeable folks. It looks like spaghetti in there to me. Lotsa wires. See attached pic (if I can figure how to do that)

It's just an off / on rocker with 2 paddle connectors. Can I just tap into any red for positive (on) and any white for negative (off)?
Thanks in advance for your help.

[kenandterry]

I'm in the middle of troubleshooting my control panel right now. I think I've determined White is usually negative (-) or ground. The 12V (+) can be a variety of colours....not always red.

You need a volt meter to test each case.

BTW....are you putting in a new rocker switch to control your LED inside the panel to light it from behind? There's not enough transparent material on my control panel to light from behind.....also won't you need to light the switch to see it to turn on the LED?

[Jeff95814]

Thanks for the reply Ken. I have a volt meter, but frankly don't know what I'd do with it looking at the mess of wires in the control panel.

My panel is recessed about 1 inch behind the hinged cover. My plan is to line the inside recessed area with my 1/4 inch LED strip. I'll post a pic when I get it done.

I considered a lighted switch, but decided for a non-lit one for battery conservation purposes. I have enough vampires already.

Unless I can figure which wires to tap into, I'm gonna have to go with trial and error. I can't mess things up too much - I hope!

[Dwilcox]

If you have a light switch in there, find a good ground the with the switch you are testing off, one side should be hot the other not. Tie into the hot side for the new switch.

[Jeff95814]

Should I tie into both sides of the light switch? One side hot, the other not?
Assuming any colored wire would be the hot one and the white is not?

I'm really dumb when it comes to electricity and wiring and such. Thanks for your help.

[Dwilcox]

No, one wire from the new light, the ground, goes to ground. The other wire from the light goes to the new switch, then the other side of the new switch goes to the hot wire. Hope this helps.

[rbrand]

You always want to control the Hot side.

[Jeff95814]

Okay guys, that helps a lot. I think I got it.

Two wires on the light; red and white. The red goes to the switch, the white goes to ground.

The switch has 2 contacts; one will have the red wire from the light. The other will be connected to a red (or other colored) 'hot' wire.

Is that it?

[Dwilcox]

By jove I think you've got it.

[PenJoe]

A switch is an interruption device on the positive side. So, once you locate your power source, wire from the source to the switch to the positive side of the LED. It appears that white is the negative and and tapping white to the negative side will complete the circuit. LEDs are polarity sensitive because they function like a diode (current only flows one way). If wired in reverse, they will not light, but they will not be damaged either.

Make sure that the circuits you are checking are 12 volts. Red is the most common color for positive, but black can be either + or -. As for using "any red wire", it depends. If they are running in parallel, the answer would be yes. If in series, no because it may be interrupted. White is most often neutral (-) unless it is used in a three-way switch configuration. Green is most often a ground wire. If you can find a red wire coming directly off the panel, it will be +. If not, look for a red wire that has multiple wires attached with a wire nut. That would be the supply point to tap into. Any white wire attached with a wire nut should be OK for the negative. If you get into automotive wiring, color coding is a whole different story.

As you indicated, it looks like a bunch of spaghetti, but once you start tracing them, it will start to make more sense.

[Jeff95814]

Thanks PenJoe, that really helps me figure out the spaghetti.