Thread: 3rd brake light LED retrofit

Copy pasted from F150OL.

Well the time has come. The other week I was in another vehicle driving behind my truck for the first time ever since my LED retro and instead of enjoying it, I was disgusted. Yup. With that darn CHMSL (Center High Mount Stop Light, also known as 3rd brake light). The 912-series incandescent draws about ~300 milliamps @ 3.5 watts and only puts out about 15-25 lumens. That means that when compared to my brake lights, its really dim and slow to light. So we're going to change that.

Right now I have (on order) all the parts for this simple retro. I'm going to be using the standard 5mm Superflux LumiLEDs (same ones in my tail lamps). Compared to the numbers above, I'll be dropping heat output to almost nothing (912s can get quite warm), from 1 amp draw to about ~140 milliamps, from 12.5 watts to .25 watts, and most importantly- increased from 35 lumens to 50 lumens :banana:

Parts list:

1x 90x150mm (3.5"x6") PCB: $4.47
10x Philips-Agilent HPWT-DH00 Red-Orange LumiLEDs: $0.00 (It's good to have friends!) MSRP: ~$10
1x Sharp 12vreg: $0.72
2x 1/4w 22ohm resistors: $0.16
1x47uF electrolytic: $0.07
1x 0.33uF tantalum: $0.18



Total Cost: ~$6.00

That right. A measly SIX dollars and a little elbow grease and solder will have you clean OEM-looking housing (versus the gaudy eBay ones from China), and over DOUBLE the output. Not to mention these aren't cheap components, so I know they won't burn out on me.

The great thing about this retro is its so straightforward. No PWM since its a simple on/off switched power. Just solder the LEDs to a board, solder the resistors in-line, put a vreg at the front, connect the dots, and trim the board to fit inside the housing. Here is my array and cheat sheet:



I'm waiting on Digi-Key to send me the vreg and resistors, my PCB to come in from Jacksonville (thank you eBay), and the LEDs are coming from California. Hopefully I'll have this mod done by the time Sun 'N Fun vacation comes around (two weeks from now).

Since no thread is good without photos:









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Presents:







The array I'm going to use:



I'll likely dismantle my CHMSL tonight after I get some HW done. Just waiting on my caps to arrive and I'll go ahead and get it installed

Looks sick! You're pretty good at that stuff

New pics:

id rather just a light from recon
http://www.gorecon.com/product.php?p...09-12&p_cat=32

I made my taillights as well (see below). They are OEM with the reflective material painted black, so with the red lens, its like a blood red instead of bright and shiny red. I can make some for you, for about the price of Recon units.

I've had Recons as well. They are overpriced crap. They are what motivated me to do this retro. The LEDs are little chinese knockoffs. A few of them were flickering and dying. Plus when you stepped on the brake, there was barely any noticeable brightness difference. That's because Recon was just putting the truck's stock voltage directly to the LEDs instead of using proper voltage control and pulse-width modulation control for luminosity. See below:

Running lights (Recon on the left, Mine on the right):



Brake lights:



Look at the brightness difference between the running lights and brake lights on the Recons versus mine. Just goes to show how important proper lighting control and technique is.

Recon taillights- $299.95
My taillights- $52.75