Nick,
I put a decoder in a MP 2-8-2 but I left the headlight the way it was. No problems. Just as long as the decoder is isolated from the frame it will be fine.
Gary
It won't fry the decoder as long as no decoder wires are connected to the light. (except red and black)
As David cautioned, watch the heat. That bulb will be getting 12 volts all the time. Unless the loco was run at full speed 100% of the time, it never saw that much voltage.
BTW, you also want to make sure that there is no more than 12 volts on the track. Bulb won't last long if actual track voltage is higher.
Martin Myers
Alright thanks a lot.
I'll send you the bill if it fries the decoder...
:)
I've got an n scale model power 4-6-2 with a dz123 in it, and everything is fine except for the front headlight. Because of the size of the frame/body, I can't run wires from the headlight to the decoder in the tender. So the headlight hasn't been wired. Since I'd like the light to work, I'm wondering if I can just wire it up the way it came (DC mode). Originally, the bulb received power from two prongs that touched the neighboring drive wheels (one per rail). When I switched it to DCC, I simply bent the prongs up so they no longer touched the wheels. If I touch them back to the wheels, will this short the decoder out? I know I will not be able to program the headlight, and I'm alright with that. I don't want to destroy another decoder just to test this though. I'm pretty sure it's a 12v bulb as it was wired directly to the track power, no resistor, and the bulb's intensity differed with the track voltage.
Thanks.
Nick