Scion XB Forum banner
1 - 9 of 9 Posts

· Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Hey Guys,

I just got a 2008 Scion XB, and in an attempt to be cool as f*ck decided to install some LED strips in the footwells. So I tapped the brake light circuit with an add a circuit as it is the only readily accessible circuit that activates with the running lights.

The illuminated footwells loo work great! However I seem to have burned out the backlight circuit for the HVAC controls and radio.

- I do know from doing some research that the backlight circuit is associated with the GREEN wire in the dash harness.
- This circuit is associated with the brake light circuit which is not blown.
- My gauge cluster still lights up but the dimmer no longer works.*I attempted to bypass the dimmer but this did not solve the problem.
- Removing the ADD a circuit and led strips doesnt solve the issue
- Every other component and light in the entire car works flawlessly

I have read a lot of threads about owners of Xbs and Tcs that have experienced the same problem after installing aftermarket radios.

Does anyone know where the weak point is in the console backlights so I could replace it or bypass it and remedy this situation? Any help is greatly appreciated.


Cheers
 

· Registered
Joined
·
1,033 Posts
Hi illikiwi, sorry to hear about your troubles. When I wanted to add a wire to sense when the parking lights are on, I also could not find a good place to tap into the fusebox. So instead I tapped into the light switch wire in the dash:
https://sites.google.com/site/brickpigs2011xb/home/ht-4---rm-light-control-panel

Alternately, you could tap off one of the clearance lights, either in the front fender or rear corner. The front fender is a slightly shorter wire run, and you can enter the car interior via a new hole the rubber door conduit. If you choose the rear corner, you have a longer wire run but are already inside the car and the wire is sheltered.
https://sites.google.com/site/brickpigs2011xb/home/ht03---rm-sill-kick-panel
For either run, you'll need to have an inline fuse in the new wire run just in case.

Good luck!
 

· Registered
Joined
·
457 Posts
Did you check the fuses above the driver's side kick panel? Sounds like you just blew one of the illumination fuses.

Also when ever you are adding a power draw to the car I always recommend using a power line from the battery, fused of course. You then use the parking light wire as a trigger for a relay to switch the power for whatever you added. This way you have a good solid power feed and you are not trying to over tax circuits by adding more draw to them than they were designed for. you also get the advantage that if you decide to add more lighting in the future you already have a good strong circuit to use.
 

· Registered
Joined
·
1,033 Posts
Greg's suggestion of a relay is a good one, especially if the lights that you add draw a lot of current.

In my case, since I simultaneously replaced some of my OEM light bulbs with LEDs (which draw less power than the stock bulbs) I was OK with adding a limited amount of LEDs to the stock circuits. Your Mileage May Vary.
 

· Registered
Joined
·
7 Posts
Discussion Starter · #5 ·
thanks

Im running just two 12v led strips, the add a circuit has its own 5amp fuse. The circuit that is not getting power is the green circuit that brick pig tapped. Perhaps I am mistaken but this seemed to have been powered by the same brake light fuse.
 

· Registered
Joined
·
457 Posts
The green wire is the parking light circuit, not the brake light one. Brake light circuit only turns on when the brakes are pressed. There are a few circuits that all trigger the same, parking lights and dash illumination being the two main ones. It sounds like you tapped into the dash illumination circuit. I believe there are two of them so it is most likely one of those two fuses that blew. You'll need to either pull them out and visually inspect them, or if you have a multimeter you can test each half of the fuses in the interior fuse box.
 

· Registered
Joined
·
7 Posts
Discussion Starter · #7 ·
I definitely tapped the Brake light circuit as I used an auto zone add-a-circuit and tapped directly into the fuse box. I used a multimeter on the fuses themselves until I found the one that activates when I turn on the running lights/headlights, it was labeled tail light. I hope that you are correct and the HVAC backlights are on a different circuit. I inspected the fuses with the multimeter, but i will check again. Is it safe to assume that all circuits will be powered when the car is on with key in the ignition? I would like to know for sure that the hvac lighting is on a different circuit.
 

· Registered
Joined
·
457 Posts
OK, tail light makes a lot more sense. That is also known as the parking light circuit so it is the correct one. The HVAC lights are triggered the same but come after the dimmer control so your problem might be in the dimmer itself. I'm almost wondering if the dimmer line going to the HVAC and radio might have been pinched by a screw accidentally. Best I can say is to look over the whole install very carefully and see if there is anything out of place.
 
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top