Ditch lights on an HO Athearn GP40-2

I took this picture about 10 minutes ago... Very satisfying!



It's my first attempt at either constant lighting or ditch lights, in an Athearn GP40-2. I made a constant lighting circuit from cardboard and diodes I bought on eBay, and drilled holes in the pilot to insert microbulbs. The four bulbs are left over from a Genesis SD70 that had one of the six not working and a second broken (by me).

Has anyone had experience with Cir-Kit micro-bulbs? They're half the price of many others from HO model manufacturers and are the perfect size for Athearn headlights. I'm thinking of buying a bunch to retrofit in my fleet.

Can you tell me how to do this circuit board? i ve been thinking of adding ditch lights to my locomotive fleet.

It's pretty easy as long as you're familiar with soldering. Here's the diagram I used as a reference--you'll need six diodes per engine:

http://www.mrollins.com/constant.html

I didn't have any perf-board to mount the diodes so I used cardboard with holes to hold the leads, and it works perfectly. (I found out from experience that the diodes really do need something to hold them in place)

The diagram says to use 1.5V grain-of-wheat bulbs, but I used four 1.5V microbulbs all wired in parallel.