Electrical problem

Help! I place a loco on my track and it takes off at full throttle. I have tried 3 different locos different track including a strip of test track and they all behave the same. This is happening when using an older MRC power pack. None of the locos are DCC. When I switch to a Digitrax Zepyher pack the engines sit on the track and make a low humming noise with dim lights. I have no control over direction or speed on either pack. Can anyone help?

Without more detail it is hard to tell. If the locos all take off the power pack is probably shot and putting power on the track at all times. Or you are incorrectly wired to the wrong terminals - many packs have more than one output. If the locos are not DCC why are you monkeying with Digitrax?

Sounds like your old MRC pack is shot. A non DCC engine should ‘hum’ when sitting on a track powered by a DCC system. If you select address ‘0’, it should respond.

Jim Bernier

SOUNDS like your MRC is putting out 12 volts OK,but the reostat isn’t functioning.
Do have the knob turned all the way counter clockwise?
Do you have the right pair of screw terminals connected?

SIMPLE questions, but your problem has a simple answer. For example, Have you tried calling MODEL RECTIFIER CORPORATION?

Sounds like you’re hooked to the wrong terminals and/or you have two loops on two different transformers connected together without insulators.

It sounds to me like you have the power pack connected wrong. The track should be connected to the two terminals marked “Variable DC” on the back of the power pack, and the throttle knob should be turned fully counter-clockwise as its “off” position. The fact that the locomotives won’t run when you use your Digitrax DCC system is normal if you don’t have decoders in the locomotive(s) and have their address selected.

some power packs have a fixed dc terminal along with variable dc. fixed dc is full 12 volt dc and variable dc works through the control knob.