Wiring LED lights to a 9 pin harness

[IDRick]

I'm in the process of converting my locomotives from DC to DC with a dummy DCC plug.  Eventually I will convert to Rail Pro.  The first two locomotives are Athearn Blue box.  I have watched a Digitrax video on how to convert the athearn to a nine pin harness.  I purchased a kit to convert my head and rear lights to LED, see: https://www.ebay.com/itm/173597511859?ul_noapp=true
 
I visited a friend that is DCC guru on another forum.  He suggested the following wiring approach:

Resistors go in either wire, doesn't matter, but according to the pictures on eBay, the red wire connected to the LED is + and the white wire is -. Resistor can go on either one, there is no direction to resistors, but there is for LEDs. Since the Railpro receivers work with the 9 pin harness, the blue wire from the harness will be the + side.

For the dual headlights, put a resistor on each of the red wires. Tie the other side of the resistors together, and to the blue wire. Tie the two white wires together and to the white wire on the harness. For the rear lights, it's the same, except that the white wires from the LEDs go to the yellow wire from the harness.

Do you agree with his proposed wiring approach?

Thanks,

Rick

[Alan]

Sounds right.

[gcarter1945]

Basic wiring as you described it should work just fine.

However, I gotta ask, how many LEDs and Resisters did you get for your $29.00?

One can acquire 2mm Tower LEDs from LighthouseLEDs.com for $0.21 each, unless you want to buy in quantity, then you can get them for as low as $0.13 each.  The 2mm Tower fits perfectly into the light socket on the blue box GP/SD 7 thru 45 if not more.  They also have resisters starting at $0.10 each.

Geoff

[faithie999]

thanks for the link to the LED supplier website.

1). what value resistor do I need for the 1.8/2 mm round top LED's?

2). my first conversion is an atlas RS-1.  the acrylic light guides project too far into the chassis to allow the decoder module to fit.  I can remove and trim them.  what do you recommend as an attachment process to fasten the LED to the end of the light guide?

thanks!

[Alan]

Use the info from Lighthouse LEDs  https://lighthouseleds.com/2mm-tower-cool-clear-white-led-ultra-bright.html



combined with your specific railroad info to populate the calculator at  http://www.ohmslawcalculator.com/led-resistor-calculator

[faithie999]

neat tool--thanks!