where to look for a "light" short?

I have a sunset brass,B11,0-6-0 that is giving me fits.For the most part,the engine runs fine,but at times develops a short.If the sound is off,it will suddenly pop on or if it’s on it will crack,lights will blink and if going slow enough,just stop.It usually happens when crossing over live frogs(both shinohara and/or peco) and sometimes on a 24" radius curve flex track.I’ve run it for what seems like hours in the dark,but can’t see any spark.My next step is to put clear lacquer on the backs of the wheels,but that seems to be only a short term solution(if it works at all}…What else might I look for?

I just had a cheap head light in a Mike cause a similar problem. The insulation at the base of the bulb failed and as it went into a turn would short out and stall the loco (DC).
Changed the bulb, stopped the problem.(pulled my hair out for 3 days though)

In My experience, Brass steam is VERY picky about the track that it runs on… Even things like the wheels touching the brake shoes can cause a short… I’m a little suprised you are having touble with an 0-6-0 however, it’s usually the lead or trailing truck that gives me a problem… Run the engine as SLOW as you can through the trouble areas. Watch what happens to the wheels and what they may be touching… Are the tender wheels touching the tender floor? Are the insulated wheels on the loco brushing against the frame? Things like that. It might also be worth looking at, Are you Sure it’s a Short? Could it be that you’re losing contact between the tender and the loco at the drawbar? It’s not always the most reliable of connections. On my brass steamers that have DCC installed, I’ve bypassed that mess with a wire and just use the drawbar for just that… A mechanical coupling between the loco and the tender (no electrical).

Good luck…

YOUR SUNSET BRASS 0-6-0 didn’t come with a Sound module or headlamp initially. A SHORT and an OPEN have the same symptom’s. OPEN’s are loss of connection and SHORT’s cause circuit breakers to kick in.

I SUSPECT an open because someone has wired-in a lighting unit or a soundmodule, and bad connection’s / cold soldering joints are common problems. Same for home wired DCC.

You’ll never know until the non-factory add-on’s are disconneted, to see if it’s them or the engine that’s causing the problem.

If you have the skills to do this - fine - if not, send to Tony’s Train Exchange. He can spot and fix the trouble. That’s his business.

Shinohara made turnout’s with hot frog’s shouldn’t cause problems nor 24" radii. Most common electrical problems wth brass engines is when the Drawbar screw & nut is loose, or when a tender truck gets reversed.

See if the tender is touching the locomotive on sharp curves.