Decoder gets warm

The other day I noticed that the top of my SD40 was noticeably warm to the touch. I had running the loco under quite a load and wonder if this would have caused the excess heat or am I looking at a potential failure.

Are you using light bulbs or LEDs? What brand and model decoder is it? Before the installation did you test the loco for amp draw? Some decoders will get warm under heavy use. How they handle the strain will depend on how long it will last.

Pete

Tsunamis get very warm, if that’s what you’ve got.

Heavy amp draw on the decoder can cause it to get warm. If the motor/drivetrain started binding up a little that could be a big source of extra draw. You should be able to pull until the wheels slip without the decoder getting too hot. A slipping motor/wheels draws less current than a stalled motor and that’s why I might be more concerned with binding.

Richard

Practically all sound decoders today have built-in thermal circuit breakers that will shut them down before any significant damage is done.

Mine get pretty warm during ops sessions. You should be fine. They really should do something to vent the shells of sound loco’s.

Thanks for all the great info. I ran the loco without a load and the decoder (Digitrax DH123D) was fine. After reading the comments and knowing that it under significant load accounted for the issue.