MTH Lighted X-mas Cars

Dunno about the durability of the MTH lighted cars (we have several of them and AFAIK they're holding up fine, but this is only my first year with the RFC train garden), but the replacement strings of MTH LEDs can be put to other uses (and have worked fine so far):

No problems at all with the lighted snowman car my wife bought me a couple of years ago. It's a crowd pleaser.

Paul

I had trouble with my lighted Santa and reindeer car. I had to take the car apart to repair. The very thin wires are held together with tape and solder. As I recall, it was a loose connection under Santa's sleigh. There has been no problem with the rest of the MTH Christmas cars.  As @Railrunnin says, they are impressive cars.

I absolutely love these lighted cars and have repaired my fair share of them.

Things that can go wrong:

The earlier ones use a linear regulator (7806) and the thin single sided circuit boards could fail from the car being dropped or hard vibrations from rough handling or track that jolts them. Basically, the weight of the wires, capacitors, and the circuit board all hanging and mounted using the 3 legs of the regulator could rip a trace.

The MTH service tech information service_bulletin_111717a.pdf contains the exact resistor value used for various LED lit items.
100 Ohms for the flat and boxcars,
150 ohms for roadside stands and houses (because they have different light strings).
(both values used 1/2 watt rated)

Further, the LED strings are just enameled wire and held to the cars with basically tiny metal staples. The wires can rub through and short to the staple or in an extreme case, short heaven forbid into AC chassis or frame with how they are routed. If you see a dim or flickering LED string on a car- stop running and fix this. I use the UV curing glue drops on the staples to prevent the wires from moving and rubbing.

Newer cars likely are using switching regulators. These are great, less heat, but they have a limitation in that they WILL NOT take a voltage spike. In other words, if you run these with postwar engines or have postwar items like gate crossings and insulated rail sections- those older postwar items have lots of inductance and sparks and tend to create spikes in voltage. How do I know this? I had a display track at a trainshow with one of the new cars on display. A person wanted to test an old pullmor based train at the show and set it on the track and used the Z1000 transformer to try to manipulate the E unit of the train to cycle- and that motor and that faulty train with arcing and failing e-unit fingers, along with the inductance blew the switching regulator module sky high in the car on the same track.

Again, this newer style regulator does not take voltage spikes well- also seen here https://ogrforum.com/topic/mth...boose-electric-short