I too would suggest going to LED's for all lighting on locos (and other places as shown in the auto). I use 12 volt warm white LED's in my locos and don't have to bother with the resistor ( just another solder joint to do and sometimes a little crowded to fit into the loco). I get mine from LED Switch Co for about $5.00 for a pack of 5. The photo is my Rivarossi Challenger with a 12 volt LED headlight and also a rear light.
-Bob
Life is what happens while you are making other plans!
Dim Bulb?
Sorry, I thought somebody called my name!.
Seriously, you can test the bulb with a 1.5 volt battery. Disconnect the bulb leads from the circuit board and connect them to the battery. If the bulb is bright it is obviously 1.5 volts. If it only glows then it is likely 3 volts or there abouts.
Regarding switching to an LED I would encourage you to push your limits. You will need a low watt soldering iron i.e 15 watts (I am guessing $15 - $20 at Radio Shack) some rosin core solder and some 1K ohm resistors (also available at Radio Shack). Walthers can provide 'golden white' LEDs. There are other sources with cheaper prices but I suggest keeping it simple at first. I am guessing at Radio Shack being able to supply what you need because I am in Canada and Radio Shack abandoned us a few years ago. Others may be able to suggest better sources in the US.
Anyhow, what may seem daunting now will become easy with a little practise (and a few screw ups - that is how you learn). Once you have experimented with LEDs a bit you will discover a whole new world of opportunities. I suggest working with 3mm LEDs at first since that will likely be the size you need for your headlight. In addition to your loco headlight, try putting a few into a structure for interior lighting. I have recently discovered SMD 0603 LEDs and I am having a ball installing them in HO scale car headlights and making near scale overhead lamps with them. Here is my latest headlight install in a Mark 10 Jaguar:
Feel free to ask more questions. Lots of people here will be happy to help.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
So there is no resister on the current bulb circuit? Or did you use the factory light board?
I assume this is HO. It's been awhile since I did my install (NCE), but I think I scrapped the factory board and just used the decoder with appropriate resistors for the installed bulbs.
I'm pretty sure you don't want to use the factory board with a separate resistor. Do one or the other, but not both.
Mike Lehman
Urbana, IL
The subject of this query does not refer to the poster, but perhaps it should. After finally sorting out issues (discussed in another recent thread) with the installation of an MRC1803 decoder designed for a Life Like P2K Alco PA, one problem remains. The light works, but it just barely glows. This is single headlight, not Mars light. I'm advised that the board is disigned to be compatible with a 1.5v bulb, which was the standard in these early run P2Ks. I'm also advised that some may have come with 3v bulbs.
Question: Does this sound like an explaination of the cause? Also, how do I tell the voltage of the bulb since it is not marked and the parts sheet does not specify voltage? Finally, I know the issue might be resolved by switching to an LED with an in-line resistor. That sounds like a electrical project that might push the limits of my talents.
Suggestions?