WHen converting these to DCC, I always replaced the Mars bulb with a regular LED, just liek the headlight, and bypassed that circuit in the back. The decoder's Mars effect was better than that oddball dual filament.
For DC operation, it should be OK to hook it to the same pads as the regular headlight, the diodes used for constant/directional lighting are more than capable of handling a pair of 30ma light bulbs. I would get another bulb like the headlight oen though, rather than try to use the dual filament bulb, just so it has a more even light.
The reference to plugging in a decoder and using the Mars light circuit is that the 8 pin DCC plug normally has one pin that has no conenction - this allows you to goof and plug it in backwards and not fry anything. Since the E unit doesn;t have a rear light, you can move the yellow wire to this unused pin on the plug, which on the P2K circuit board feeds power to the Mars circuit (actually it's the - side of the circuit, the + comes from the blue wire) thus whenever F0R is activated, the Mars light would flash using the stock bulb and circuit. If a 4 or 6 function decoder were used, the 8 pin plug still would only have 2 functions - headlight and reverse light, but you could connect one of the otehr 2 or 4 functions to that same pin on the 8 pin decoder and use that function to turn the Mars light on or off - or, replace both with an LED and configure whichever function wire you hooked to the new Mars LED to use the Mars light effect. Or Gyralight if your prototype used one of those in the second lens instead of a Mars light. Or if you just like that one better.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
When I converted my P2K E6 to DCC, I used a cheap 2 function decoder, and per instructions from Digitrax, and a diagram on their web site, I was able to get the mars light to function by resoldering one of the wires to an empty pin in the socket that was on the decoder harnes.
I don't remember what I did, or what headlight function I had before doing this.
Not that this is any help, it just got me thinking how I got the mars to work.
Mike.
My You Tube
Great tip about the consist and facing the E8 to the rear, Tom. But I won't be messing with the circuitry and fry everything. I'm hoping there is an easy method of doing this like switching a wire.
Rob,
You might be able to solder the headlight (incandescent?) to the same pads on the circuit board that illuminate the numberboards. However, that could overload something if there is a maximum amperage limit for those pads.
The other thing you could try is soldering the headlight directly to track power. The downside is - if it's incandescent - the brightness of the headlight will be dictated by the amount of voltage going to the track. At idle - no voltage, no headlight; at 6V - dim headlight; at 12V (full-speed) - bright headlight.
Or, if your are going to operate it in a consist and your other E8 headlight works the way you desire, make that E8 your lead locomotive and Proto 2000 E8 the "B" unit. The headlight doesn't need to be on if it's facing the front of the passenger car behind it.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
A Proto 2000 E8 DC only with a flashing multifilament Mars light behind a single lens (no second lens in door). There is a steady lit bulb beneath the Mars bulb that illuminates the numberboards through a prism. The circuit board at the rear of the loco has extra capacitors and a transistor(?) Is there a way to turn the Mars bulb into a steady glow if I ever want that?
Thank you all for your help. -Rob