I am considering getting a LifeLIke DCC ready E7 Maine Central Locomotive ( used) from my LHS; it runs on DC, but the light bulb doesn't light. Converting this to DCC is pretty easy using TCS decoder and wiring, I am concened about the light bulb - how do I check it out to see if it needs replacing? Just running it on dc power pack it did not come on. I understand its a special 2 filement bulb.
The headlight is a normal bulb. Unless a wire got ripped off, it's just burned out. An LED and resitor is a better option anyway.
The Mars light, if this version has one, uses a 2 filament bulb and it would be unusual for both to be bruend out, one of them should flash when under power (at at least half throttle, it may not have enough voltage to operate the circuit when just creeping along). This is also a good candidate to replace, the Mars light effect from the decoder is far superior, plus the only way to make it work with a decoder plugged in to the 8 pin is to solder one of the extra function leads to the normally empty spot on the 8 pin. Might as well just run that wire up to the front and do it right.
Edit: Also check the current drawn stalled at full voltage on DC. Depends on what run this loco is from, there was a series of them that had motors that would draw as much as 4 amps. Back in the day, they replaced them for free, but today your best bet would be to either get a chassis from one of the runs that didn;t have the high current motor and swap shells, or else fit a replacement motor from NWSL or others.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
If you are adding DCC yourself, My advice would be to scrap the factory circuit board altogether and hardwire in your decoder. The circuitry on those boards to make things flash aren't required with the use of a decoder and can just cause trouble in my experience. I did just that with my Proto PA's and replaced the dual filament bulb with a 5mm LED that flashes just fine using the settings on the TCS decoder.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
I don't think MEC E7s had Mars lights.
Ron High
If it is a used engine, the shorting plug could be in 180 out.
South Penn
I have 2 of the LL P2k E7s. Toss the boards. On mine they used regular resistors which blocked the installation of an 8 pin decoder. I ended up using an NCE D13SRJ for mine. Also toss the bulb and install a LED. They are relatively cheap and will probably last longer than you own the locomotive, plus if not properly regulated, that bulb will turn the front of your E7 into molten plastic slag. I would also recommend testing it to see if the gears on the axles are stripped (attempt to roll the drive wheels with a finger, if they roll pick up a set of Athearn SD40-2/2T gears, they fit right in).
Edit: There is space for a TCS WOW Diesel with Keep Alive and a speaker.
Ron High I don't think MEC E7s had Mars lights. Ron High
I believe you are correct.