Athearn Genesis decoder install

[Anonymous]

For the last couple weeks I've been trying to install a Digitrax DH163AO decoder in an SD70M. The problem I'm having is without hooking up any lights, it runs great. As soon as I solder the lights in and turn them on, the loco takes off at top speed. Know I'm probably missing something obvious, but for the life of me I can't figure out what. The system is an MRC Prodegy, lights are 1.5v 30mA gor with 470-ohm resisters in line. I'd appreciate ANY help given. Thanks.

[betamax]

Check your wiring, because something is very wrong.

The resistor will drop 14V at 30 ma, so there is no way you could be powering the motor that way.

The lights should be on their own leads, with a lead common to all of them.

Be sure you have not accidentally bridged the motor connections either. Or you have connected the blue lead, or one of the lamp leads, to the motor.

[Anonymous]

Thank you for the help.  I'll be tearing into it this weekend.

 

Thanks, Mark