2005 Signature (and others) 18" third brake light - DIY Replacement

[pwhittle]

Hi all,

The third brake light on our 2005 Monaco Signature started going out (again) and it is no longer available. I replaced it once not long after we bought the coach with the same  original part from Veurinks, and after it faded, I painted it with a red plastic lens paint to restore the red color. Then it cracked in the middle and the individual LED's started burning out.

Part number from Owners Manual: MP#16620607 870 51-R

Rev Parts Link: LIGHT, BRAKE THIRD | REV Parts Store (revrvparts.com)

Mouser Link: https://mou.sr/3m76ErY

DataSheet link (See Page 13): https://www.mouser.com/datasheet/2/109/Vehicle_LED_SelectorGuide-50899.pdf

I had already added a brake light flasher to the circuit for the third brake light so that it will flash four times then come on solid when you apply the brakes. That had required opening up the hole for the wires and the flasher to pass through. The SAE connector was installed at the same time.

I 3D printed up some mounts and used a YW aluminum LED Channel with a LED Strip. in the mounts I included a recess for the clip that comes with the YW channel. I also used the end caps that came with the YW channel. 

The hole in the 3D model is sized so that the 3mm machine screws will cut a thread in the mount. After printing the mounts, I used 3mmx3 machine screws to attach the clips to the mount, and installed the mounts in the original holes on the coach.  On our coach I had to grind away some of the back end of the left mount as the recess was not flat in the back. Once the mounts were in place I measured between the two raised ends and got 16 1/4" as the total length for the channel. I took off 1/16" for the width of the end clips and cut the YW channel and clear cover at 16 3/16" on my vertical bandsaw.

The LED strips have specific locations where they can be cut, and you can add power to anywhere on the strip. These are marked with copper pads under the silicone waterproof layer. On the strips I used, they were every 3 LED's or approximately 1".

I cut one end of the strip on the copper pads and laid it in the YW channel, then cut the other end at the last set of copper pads  on the YW channel and counted to find the middle set of copper pads. On ours, there were 16 sets of 3 LED's so I marked the strip on the 8th set of copper pads, centered the strip on the YW channel, and marked the YW channel to match that location.

I used that mark to drill from the outside of the channel parallel to the base with a 1/8" drill to make a hole that I could pass through the 16ga wires I was using to a two prong SAE plug. i would have used a 7/64 drill and an 18ga wires if I had them, but I have linked that below in the supplies. I deburred the hole with a small round file.

I carefully removed the silicone from the LED strip to expose the central copper pads for soldering. I used a razor blade to cut the silicone just inside the LEDs either side of the pads and then was able to peel away the silicone. (This was a test cut on a shorter piece)

I cleaned the YW aluminum channel and stuck the LED strip in place starting in the middle to make sure to align the central copper pads with the holes. I tinned the copper pads (used flux and solder). I stripped 1/8" from the end of the wires, passed them through the holes, and soldered them to the copper pads on the LED strip, being careful to connect ref to +ve and black to -ve. I checked to make sure that neither the +ve nor -ve was shorted to the YW aluminum channel. Note that if I tinned the wires before passing through the hole, the insulation swelled with the heat and would not pass through the hole.

I covered the soldered pads and the area I had removed the silicone from with fresh silicone, and applied silicone over the wires on the back as they exited the channel. I also filled the hole in the end caps with silicone.

I sprayed the clear LED strip cover with red lens paint to have the red appearance as original. You could also leave it clear.

Here it is installed.

And running with the hazard flashers. the third brake light will flash 4 times and then stay on normally, but I did not start the coach so I could press the brake pedal.

Running.MOV

 

Sources for parts:

3D Printed Mounts: I printed these in white ABS with 100% infill.

YW Channel: I ordered mine from China on AliExpress. I do see some on Amazon and eBay, but they all seem to be shipping from China. They come with options for clear and milk lenses, and we want the ones that have two clips and two end caps as we use them. The clips I received and what I made the 3D Printer mount for are 9mm wide.

AliExpress Link: https://www.aliexpress.us/item/2251832693313513.html Select YW Style,  50CM Transparent

LED Strip: https://a.co/d/1SZPTxm

Red Lens Paint: I used VHT888 Nite-Shades Translucent Red lens paint. It does not appear to be available any more, but there are likely other products out there.

Brake light Flasher: https://a.co/d/7DR5Jms

18ga SAE Extension: https://a.co/d/6ST2xE7

Paul

Edited February 26, 2023 by pwhittle

[jreich888]

Very nice and thanks for sharing the STL file.  I don't have a need for this right now, but good to have models available if I need to tackle the same thing.  I've created a duplicate window latch for the atwood lift windows for our RV (https://www.thingiverse.com/thing:2480496). 

One word of warning for the ABS prints, I've found unprotected ABS will get brittle with UV damage after time.  You don't mention if you painted your mounts or not, but you may want to get some paint on them to protect them.  I've also read ASA is similar to ABS but better UV properties, but I haven't tried that.

Thanks
Jason.

[vito.a]

What a great job!  Thanks for sharing.

[pwhittle]

1 hour ago, jreich888 said:

One word of warning for the ABS prints, I've found unprotected ABS will get brittle with UV damage after time.  You don't mention if you painted your mounts or not, but you may want to get some paint on them to protect them. 

I have not experienced that yet, but will keep an eye out for it.

it will be easier to reprint them than paint them. :j

Paul

[Guest Ray Davis]

Paul,  I'll tell you what,  you and several others continue to amaze me with your projects and knowledge.  That is beautiful work, if I was only 30 yrs younger.  

[Ivylog]

When mine stops working I’ll probably use these over the recess.

[pwhittle]

3 minutes ago, Ivylog said:

When mine stops working I’ll probably use these over the recess.

You do you Dick, but that would look pretty bad on my coach.

Paul

[Mike H]

Paul, When mine started to fail I discovered that PREVOST used that same light that came on my '05 Exec.

[pwhittle]

Hi Mike,

That is the same Dialight manufacturer data sheet that the second Mouser link above goes to.

I wonder what the Prevost people are doing for replacements?

Paul