Make sure all wheelsets are installed the _same_way_
Dear James,
Check the wheels on each individual wheelset closely,
Strongly suspect that you'll find there is a plastic bushing,
or in the case of early brass models even a single thickness ring of paper,
acting as an insulator, between _one_ of the wheels and the axle.
(The _other_ wheel is likely mechanically and electrically connected to the axle).
Now, here's the killer, make sure the _isolated_wheel_ on _each_wheelset_ is _consistently_ installed on _one_ side of the car!
Because the trucks are also metal:
- (Forget about the entire car for a sec, focus on 1 truck + 2x axles as a standalone assembly),
axles installed "opposite" in a metal truck = short between axle<> truck<> axle
(lesson learned: install all axles in a truck with the insulated wheel on the same side of the truck)
Assuming above is OK
- 2x trucks installed on a metal-bodied car, with insulating "sides" on opposite sides of car
= short between axle<> truck<> bolster<> carbody<> bolster<> truck<> axle
(lesson learned: install all trucks on a given car with the insulating wheels on a consistent side)
Assuming the above is OK
- check whether the brass or kadee couplers are insulated from the car frame/body.
This is critical because, even if you've covered both points above,
couple 2 X brass cars together, where their "insulating wheels" are not on the same side,
(car A's insulating wheels are on the North rail, car B's insulating wheels are on the South rail),
and you _may_ see an intermittent short thru the couplers
car A axle <> truck <> car A carbody <> coupler <> coupler <> car B carbody <> truck <> car B axle
A similar fault condition is common to blue-box Athearn diesels,
because they use the metal frame as both the coupler mount, and electrically connected to 1 "rail"...
(couple both locos head-to-tail = OK, tail-to-tail _without_ insulated couplers = short circuit)
Hope this helps...
Happy Modelling,
Aim to Improve,
Prof Klyzlr
