Installed a DH123 into an old Athearn PA1. Motor works fine but I can't get either of the two led headlights to operate. Have installed twice, using different sets of 3mm leds and 1k resistors in the same manner as several other engines. Have continuity between the leds and the decoder. Any suggestions?
LEDs are polarity sensitive. It sounds like you have them wired backwards. Try reversing the wiring to them. The blue decoder wire is the positive output to the LEDs and the white wire is the negative.
And you have to turn the headlights on by pressing FL or Function 0 on your controller.
Reversed the leads. Had a senior moment and read things wrong. When all else fails, read the instructions.
However, now I have another problem. The backup light stays on all of the time. The headlight can be control by the switch and goes off in reverse. Messed with the CVs and did a factory reset and the backup light will not go off. Any ideas. Thanks for the help.
CV 49 controls the headlight (white wire) and CV 50 controls the backup light (yellow wire). The Blue positive wire should be connected to both lights.
Real locomotives do not have directional lights. For more realistic operation the headlight should remain on when the locomotive is backing up, and the backup light should be on only when backing up. Usually the headlight is dimmed when backing (Rule 17 lighting).
If everything is wired correctly set CV 49 to a value of 28 to have the headlight remain on but dim when backing up. Set CV 50 to a value of 10.
If you haven't already done so, you should download the Digitrax Mobile Decoder User Manual which explains all of the various lighting effects available.