Kurtiss' GT-R

Hello Kurtis,
I quick question regarding post #286. The diode that you used for the third/center brake light. Is it needed because the ligh is LED? I'm wiring my tail light circuit now and glad I caught that post. Also do you happen to have a Amazon source. I tried pulling up the part number shown on the diode but no luck on Amazon. Appreciate any help you can offer.

Rob..
 

Neil

Supporter
Hello Kurtis,
I quick question regarding post #286. The diode that you used for the third/center brake light. Is it needed because the ligh is LED? I'm wiring my tail light circuit now and glad I caught that post. Also do you happen to have a Amazon source. I tried pulling up the part number shown on the diode but no luck on Amazon. Appreciate any help you can offer.

Rob..
It is just a "Diode OR" circuit.
 

Kurtiss H.

Member
Supporter
Hi Rob,
Sorry of the slow response. You're right, it's difficult to find. This is needed to prevent a left or right turn signals from flashing the Center High Mounted Tail Light (CHMTL). You only want it to illuminate when the brake is applied. I found the converter diode on Amazon when searching for "Center High Mount Brake Stop Light Converter Diode". I found one on Amazon HERE
Hope this helps.
Kurtiss
 

Neil

Supporter
Hurley,

A "Diode OR" circuit is a simple digital logic circuit. It has 2 (or more) inputs and one output; When one or the other of its inputs get a voltage, its output puts out a voltage. If none of its inputs gets a voltage, its output is zero.

Here is how it works: L & R brake light OFF = C brake light OFF
L brake light ON & R brake light OFF = C brake light ON
L brake light OFF & R brake light ON = C brake light ON
L brake light ON & R brake light ON = C brake light ON

I didn't have a symbol for a light bulb but I hope this diagram helps. The individual diode types are not too important, just make sure they can handle the current required for your center brake light. The voltage rating is insignificant since this is only a 12 volt application. Diodes power diodes are rated from 50V up to 600V so get whatever is cheap & available.
 

Attachments

  • DIODE OR.JPG
    DIODE OR.JPG
    15 KB · Views: 289

Chris Kouba

Supporter

FYI - These use relays (or at least I hear something clicking when used). I have one on the camper to separate the turn signal lights from the brake lights. That is effectively the opposite of what the diode circuit does.
 
You should be able to get 100 diodes for $12.
Better is wire the brake light to the actual brake switch before the turn signal.


Just using the pair of diodes will flash your 3rd brake light when you use the blinker.

Just saying...


Didn't see the other post. I guess the module somehow keeps the blinkers from interfeering, but still, wire the third brake between the brake switch and the blinker switch and avoid the module.
 
Rob, that same exact converter diode is on Ebay for $12.00 less with free shipping also.



Regards Brian
Well I'm a day late and a dollar short as usual. I already ordered the one Kurtiss found.
 
View attachment 123520

In this example, just connect the 3rd brake to the red wire.
Thank you Brian. This is exactly the way I had planned to wire it originally. However, I am running the master cell which is completely new to me. I think I see why Kurtis is using the diode now. I just thought of something. If the master cell system grounds out the brake switch to complete the circuit. Any reason I couldn't run a fused hot to the center brake light and let the same switch ground out the light completing the circuit?
 
I wouldn't.

The mastercell may only have a 5V pull up that the switch is grounding, and the light backfeeding 12V to the electronics could be dangerous. Might be fine, but might harm the mastercell of the MPU isn't properly protected internally.

I wouldn't do anything conflicting with their install instructions. BUT, they may have an output specifically for the 3rd brake light.
 

Kurtiss H.

Member
Supporter
Gentleman, please don’t hijack my thread.
Rob, I agree with Brain, there’s a chance of backfeeding 12V to the Mastercell – not good. You could use a double-pole brake light switch or Infinity Box may be able to reprogram the Mastercell for a third brake light. Since my wiring was 90% complete, I went with the CHMTL converter diode (made it easy and works great).
 

Brian Kissel

Staff member
Admin
Lifetime Supporter
Yes Kurtis is correct, please let him have his build thread back. Any future questions should be in their own threads.

Thank You
Regards Brian
 

Kurtiss H.

Member
Supporter
Yes, I'm getting close...
Finished assembling the doors except for the red trim (install after the seats are in) and the windows. The overhead piece and switch panel are in including the wiring to the rear-view mirror lighting. Second Skin soundproofing has been applied to the floor and sides and the carpet has been cut and glued into place. The center console is ready for install but waiting for the dash to be upholstered (hopefully by the end of next week).

1.jpg3.jpg4.jpg5.jpg6.jpg8.jpg9.jpg10.jpg11.jpg12.jpg
 

Kurtiss H.

Member
Supporter
There are a few things I must do before final assembly like front wheel alignment. In post #256 I modified the front suspension to remove the 1-1/2” wheel spacer but neglected to check the alignment. I used a Quick Trick alignment tool, followed their directions, and took my time. I used the SLC recommended settings for CASTER, CAMBER, and TOE-IN.
- For caster, the SLC recommended settings are Min: 4°, Max: 8°, Preferred: 5°. Changing caster is difficult due to the modifications but I found the left/right side to be +7.80°/+7.95° so I called it GOOD.
- For camber, the SLC recommended front wheel settings are Min: -0.3°, Max: -1.3°, Preferred: -0.8°. My initial was 2.78° and 1.80° left and right respectively, not quite Bosuzoku style but was noticeably off. I added spacers to the upper A-arm to chassis connections (see photo). I added 0.40” spacers to the left side and 0.20” spacers to the right and had a final camber of -0.8°/-1.0°.
- For toe-in, the SLC recommended front wheel settings are Min: 1/32”, Max: 1/8”, Preferred: 1/16”. My total toe-in is 1/8”.

1.jpg2.jpg3.jpg
 
Heck by the time you finish you will need to put it in a glass box. Amazing attention to detail.

Kurtiss was kind enough to let my wife and I peek at his car. I was able to meet Kurtiss and his wife as well. Great people. Words do not do the car justice. Our planned ten minute visit ended up being over 2 hours long. It was the highlight of my vacation. :)
 
Back
Top