4-12-2 now requires battery....why?

 Somewhere its not getting power....Alot of them lose power in a switch if its not powered all the way threw it...Even if it was sometimes it might of came lose ... I had a few ross switches that did...Also maybe a loop lost power and everything else goes threw it...I know you said you cleaned the track.. Maybe make sure sometimes theres black gunk on it and wont remove easy..

First thing to check is continuity between the rollers on the tender, if one of them has a broken wire, the sound and tender lights will be flaky.  That would be my top suspect from your description.

I have the same engine and had the same problem, called Lionel & a tech said believe it or not your track is to clean LOL! I was a tool & die maker for 23 years and made my own killer track cleaning cars, they work really well and in this case to well. He said spray some WD40 on a paper towel and wipe the center rail. WOW! It worked, it happened again on another switch so I took it up a notch I now use CRC 2-26 electrical grade spray lube. Just spray a little on a Q tip and put a little on the center rail. The problem is gone now. It worked for me, might be worth a try. Good luck.

Train Nerd Al

I forgot, I put the same lube on the pick up rollers, helps them roll better and helps with the power pick up.

Train Nerd Al

I would like to know the technical reason that the locomotive requires a film on the center rail to run properly.

Forgive me if the following seems like strong wording, but I mean to learn something from this case.

Making the track dirty so that a particular model locomotive works is absurd! What about other locomotives you may be running that require clean track? I suspect that over time, the stuff being applied to the track center rail will collect dust and get nasty.

Your saying that it needs the battery all the time, not just over switches correct?  Sounds like a board failure and it runs on backup battery if it is not the wiring issues John mentioned.

Making sure the power feeds are making it to the board.  Chassis ground and center rail pickup.  I am not as familiar with the Legacy boards.  If this was a RS 5.0 I would say check the Power Supply Board by swapping it out with a known good one.  G

I don't think the battery runs the serial interface to the locomotive, so running on the battery totally doesn't seem to be the issue.  I know the battery does not operate any lights, so if the lights are having issues as well, that certainly isn't running on the batteries.  The sound running on battery would run kill the battery in short order, a couple hours running on continuous battery would kill it.

I've also never heard of having to have dirty track, that's certainly a new one on me, and certainly doesn't mirror my experience!

I'm still betting on the connection from the rollers to the board.

imo what might be happening is the pick-up roller has a film on it and when it contacts a clean center rail it can not make good electrical contact.  I would buff up the pick-up roller and spray electrical cleaner into the pick up roller and try that.  I would not put anything on a clean center rail as it would attract more dirt. imo

Not completely true John.  On my TMCC RS 5.0 N&W J, the rear tender lights and markers come off the power in the Tender.  On a shutdown sounds and rear tender light (if stopped in reverse) remain on until battery kicks out.

I assumed he was talking about the tender lights.  Your correct it would be weird if it effected the engine lighting, but again I am not as familiar with the Legacy boards.  G

My tender lights go out immediately on loss of track power with a battery installed, I'm thinking of two different Legacy locomotives.  The shutdown sounds complete as you'd expect.

If he were running strictly on battery, it would be flat in a couple of hours at the most, so surely he'd know by now if there was no track power going to the tender.  However, one roller not connecting would have it dropping out all the time, whenever it went over a dirty spot or a switch.

Thanks for all of the leads.  Without a battery there is no sound anywhere on the layout...across several different isolated power districts (each at 18V) through Ross switches....everywhere.  The track is clean and every other engine is fine.  Also the 4-12-2 was fine until yesterday.  The engine responds perfectly to commands even though there are no sounds.

I have a multimeter and thus far have only used it to ensure I have 18V when wiring track.  I will set the meter to read ohms and check for continuity across each pick up roller.  One lead contacts a roller, but what is the path of current?  I think the wheels complete the circuit, if that is the case then shouldn't the other lead be pressed to a wheel?  Sorry, I am a real novice at this.

thanks!

What lights are on with out the battery?  Are you just talking tender lights being out unless battery is in?

If you take the tender shell off, trace the roller wires to the plug that goes into the circuit board.  Make sure you have continuity between both rollers and the circuit board connection.  Do the same for the outside wheels or chassis to the black ground wire.   G

It has to be a wire issue as the guys mentioned.  The battery is for Railsounds.  This tender uses the Railsounds Lite board.  If you pull the plugs and put them back in you might get lucky.  Those RS Lite boards do go bad.  One more thing, check for broken wires on the ground wipers.