helixx

As the title states, I'm pretty much as clueless as it gets when it comes to wiring and technical terms. I checked out https://www.scionlife.com/forums/sho...d.php?t=166093, but unfortunately this didn't help. I'm trying to do a simple hookup of small (max 6 led), under dash LED strips tapped to the dome light. What is the easiest way to do this? I've read about t taps, and add-a-circuits, but am still confused as to how exactly they work... and how exactly to go about using them. Which one requires the least bit of knowledge and ability? I'll need major details to whomever chooses to take on this difficult case. Difficult, meaning getting me to understand it. Yes, if I'm that clueless, I know I should just not do it...but it looks so darn cool, and I'd like to say I actually did something by myself. Thanks in advance.

uskrewed

T-taps work great, but they take up space, which you don't have available inside your pillar. Add-a-circruits are great too because you only need to find a ground and usually the right fuse, but I don't think they work with the switches because the door part of the circuit goes to the ECU.

Have you done any sort of wiring in the past? Even putting together circuits for fun? soldering? splicing?

The dome/map light(s) wires comes down through the driver side pillar, that is an easy way of intersecting the wire. Just tuck the wire from your LED strip under the trim at the door and up to the pillar.

Anyway, from what I can read in the wiring diagram you need to find the pink wire if you're going for the door switch portion of your dome light.

helixx

I've done zilch in the way of wiring in the past. I was kind of hoping I could pop in an add-a-circuit to where the dome light is connected to the ECU, but not sure if that is feasible...and if so, how exactly to accomplish this. Any thoughts?

Davestoaster

Dome light wiring can be tricky sometimes because of the different ways just turning on that light is accomplished.

But stay away from the ECU.

If anything use a "add-a-circuit" at the fuse box to get your power.

The hard part comes from some of the domes are grounded different ways, and not all of them through the switch in the door jamb.

Your best bet is do like the previous poster said and pick up the power behind the A piller, or at the dome light itself, which would involve fishing some wires.

helixx

Thanks for the response. I suppose it doesn't seem too difficult to splice into the wire in the dome in the A pillar. I'll give it a shot, and hopefully not deploy any airbags

edit: question...I've done a cut/twist/cap splice before, but i'm guessing that wouldn't be wise. I can handle soldering, but just wondering what the wiring configuration should be. Meaning, I cut the dome light wire I'm tapping into, and then what exactly. Since I'll be hooking up two LED strips, what should my wiring config. look like. Sorry, i'm sure this is common sense to most of you, but not me!

helixx

Ok, so I've got a wiring diagram, I pulled off the plastic bottom runner as well as the plastic piece near the brake pedal. As mentioned, it appears the pink wire is the one I want to tap into. Now I'm seeing like 4 different pink wires...some thin, one big thick one. Can anyone steer me in the right direction (this will hopefully the last you hear from me on this one). Thanks!

uskrewed

Could you take a picture of it so I can see where you're looking? I know at least one of them is the ABS wire and one of them is TPMS.

If all else fails pick up a Test Light (it has a pointy end , a light , and a ground wire) from your local hardware/auto store and check out each wire until you find the right one. It should only illuminate when your door is open

helixx

If I'd known this would have been so difficult....Well, here are some pics of what I was talking about. Again, many thanks.

helixx

So yeah, update again. I got a light tester, and tested every single pink wire with door open vs. door closed. Basically if it lit, it stayed lit. So I think I'll give up now until I can find someone to do it for me. Thanks for the help.

uskrewed

Oh, you're going after wires in the kick panel. Physically remove the A-Pillar and the wire will be in there.

2AZFEMTM1F7

i will look up the wireing harness in T.I.S at work tomorrow it should shed some light on what wire you need to use to tap into maybe there is a more simple way of hooking this up. Im going to be doing the same thing to my xb2 soon . so i would like to go through it step by step with you and see how it works out

2AZFEMTM1F7

helixx, why the need to use the dome light wire in the first place?? what you could do that would probably be alot more simple is there is a 12v constant power wire, that is light blue, that powers all the interior lamps you could do a simple conection into that. then wire up a nice simple switch on your dash?? or even under the dash out of view.

mcbrew

What you want to tap into is the pink wire, shown in red in the following diagram. You'll see the map and dome lights labeled M1 and M2:



Use a "scotch lock" if you have room for it. They are self-explanatory. No cutting required. The scotch lock has two grooves in it -- one that goes all the way through and one that goes halfway through. Clamp it on so that the power wire goes all the way through and the wire to your LEDs is in the halfway groove. When you squeeze the scotch lock closed it will pierce through both wires and make an electrical connection between the two.

NOTE: The pink wire is NOT +12V. It is a ground. The dome and map lights are connected to +12V all the time (blue wire). The lights turn on when the circuit is grounded, either manually (when you reach up and turn the light on) or by the Main Body ECU when you open the door.

uskrewed

Oops, I guess I forgot to mention that part. thanks for the save.

mcbrew

No prob. It would be possible to use the pink wire the same way the dome light works. It would just need to be hooked up to the negative side of the LED, then the positive side would be connected to a constant 12V source.

helixx

Thanks a lot for the great diagram and explanations. I decided after all this to take the easy route, using an add a circuit and rocker switch. My LEDs aren't super bright, so I don't think getting pulled over for them would be a prob. Thanks for all the input though!