Hello All,
wjstixMärklin HO uses a three-rail AC system, so the wheelsets don't insulate one side's wheels from the other. Marklin owns Trix, and often the same equipment Marklin makes for three-rail is available under the Trix name set up for two-rail operation.
I knew that about Märklin locomotives...
Well, that was easy...relatively...
I didn't realize that about the wheels on their rolling stock.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
jjdamnitI purchased a Märklin flat car intended for European use. It did exactly what you described.
Yup, Marklin HO uses a three-rail AC system, so the wheelsets don't insulate one side's wheels from the other. Marklin owns Trix, and often the same equipment Marklin makes for three-rail is available under the Trix name set up for two-rail operation.
Another quick test to narrow down the B-unit issue would be to test one truck at a time on the track. Maybe put down a thin piece of cloth or soft paper towel over the track and put one truck on it so only the other truck's wheels are on the rails. Then try the other one. If neither truck causes a short by themselves, but do when both are on the track, then there's something (a wire, or the metal chassis, etc.) that's connecting the two and causing the short.
Another common problem is a reversed truck, so the "hot" wheels end up on opposite sides, causing a short.
Is the frame part of the electrical circuit, and are the couplers electrically connected to the frame? This can happen with metal frames and coupler boxes, and metal couplers. If two engines are coupled together, they can cause a short through such couplers.
It takes an iron man to play with a toy iron horse.
All great suggestions!
Use a multi-meter, set to "Continuity" or "Beeper" [→+)))] function, and "trace" the electrical path between the wheels.
The wheels should be electronically isolated from each other on the same axle.
Place one probe on the axle and the other on one wheel. One combination will sound the tone, while the other won't.
Or, place one probe on one wheel and the other probe on the other wheel. You should get no tone or beep.
I purchased a Märklin flat car intended for European use. It did exactly what you described.
After "tracing" the electrical path I discovered that both wheels were uninsulated- -continuity between both wheels and the axle.
I replaced them with North American insulated wheels and no more shorting.
Just under the "check everything" style of troubleshooting, have you taken off the body and looked inside? Even though it's unpowered, it's possible a previous owner may have added wire connections to the trucks so they could be connected to an A unit and help it pick up power. If so, could be some wires left inside are touching causing the problem.
some manufacturers use wheelsets that have one wheel insulated from the axle and one hot with the axle. if the previous owner diassembled a truck he could have a wheelset installed so there is a short in the truck. it should be fairly east to tell if you raise one end off the rails and the short goes away.
If cracked gears are the problem in a dummy unit there is no need to buy replacement gears. Just find some plastic tubing that fits snuggly over the axles. Some epoxy will secure them if you can't find a tight friction fit.
Epoxy may even make the cracked gears usuable for a dummy unit.
Mark
tazzy45Any ideas are welcome.
I remember using several Life-Like dummies and I'd usually buy a second powered engine to use as the chassis and set the dummy aside for parts.
The Life-Like truck is designed with the gear acting as the axle AND the insulator. It is possible that the wheels on one, or both, trucks has a wheelset that got squeezed together too closely and what happens is the axle stubs inside the gear molding actually touch and cause a short.
You can test this either with an NMRA wheel gauge or if you have an ohm meter you can probe each pair of wheels and find the offending pair. Gear (axle) splitting was still common even on the dummies so it is possible that the offending wheelset has a split gear allowing the wheel/axle stubs to more easily get pressed inward causing a short.
Walthers sometimes offers replacement wheelsets. I'm not sure of a direct replacement gear that is available other than from Northwest Shortline and, at the cost of these, would be a bit of a waste on a dummy locomotive.
https://www.walthers.com/replacement-geared-diesel-wheelsets-fits-early-proto-2000-r-e6-7-8-9-pkg-3
If you turn the engine belly-up and then attempt to "twist" the wheels using your thumb and find ones that turn fairly easily that's a sign the gear is cracked. You "could" get away using the Athearn #60024 gear but be aware that these have a 12 tooth gear and the original L-L E's were 11 tooth. This, however, wouldn't have any bearing on a dummy as long as the idler gears are also removed from the truck. The dummies wouldn't normally have idler gears installed.
Good Luck, Ed
I recently purchased a Proto 2000 EB7 Unpowered locomotive. When I place it on the track with the rest of the train it short circuits. When I take the car off the rest of the train runs fine. What could be causing the short circuit when I place the E7B on the track? Any ideas are welcome. Thanks