Decoder install help?

Model Railroader Electronics and DCC
1

I just installed a Digitrax decoder into a Bachmann 44 tonner, however I realized that there was a bit of smoke from what I believe came from the locomotive. The decoder worked, it responded to address 03, and went in both directions and the lights were working. However it ran really, really slow.

So I decided to reinstall the decoder, but now when I connect the black and red wires I get a short. So I uninstalled the decoder once more, then I connected the black and red wires straight to the track rails and I still get a short circuit. Therefore it makes me think that the short is being caused by the decoder, not the locomotive. Am I correct in my thinking?

Thank you.

2

Sounds right to me. You smoked it in your first installation and something internally went bad. Now it is permanentl shorted internally.

3

Thanks for the input.

I want confirm my idea, so if I grab the black and red wires only from a decoder and have each wire touch a powered track rail, without them touching each other at all, there should NOT be any short circuits.

Is this theory correct?

4

Normally red and black should not short the system.

Below is the PC board in a DCC ready 44 ton. It was in mine. Remove two clips and solder the decoder wires. Where there any shorts between terminals?

http://estore.bachmanntrains.com/images/ho_parts/622XX-80002.jpg

I use the program track in case of a wiring error. It helped me one time when I switched the orange and red wires.

By the way, when you get it figured out, remove the two yellow blob capacitors. They are not needed.

That is a single motor 44 ton. I have two of them.

Rich