UPDATE:::::: Thanks Randy. I tried what you suggested and now the lights work in both locos.
Thank You Randy........I will try your recomendations and see what happens.
The DH165A0 has current limiting to 15ma for the front and rear lights. On the locos with LEDs - if they also have the resistors in them, this will be in effect double durrent limiting - you can remove the resistrs from the LEDs and the decoder will provide a limited current to keep them from blowing. LEDs are also polarity sensitive. If they are wired backwards, they won't work. Try flippign the connection on the two center terminals of the decoder.
For the locos with light bulbs - the 15ma output may be too low to run them. There is a jumper on the decoder you can cut to increase this to 30ma. Alternatively, you might consider replacing the ones with bulbs with LEDs and not touching the decoder.
If you install other lighting - beacon, ditch lights, note also that the other function outputs have no limiters on them. ONLY the front and rear lights have the current limiters. To use LEDs on the other functions you must include a resistor.
-_Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I just installed a Digitrax DH165AO decoder in an older HO, Atlas Classic, RS-3 and in a brand new HO, Atlas Classic, RS-1. I can't get the lights to work on either locomotive. The RS-3 has incandescent bulbs and the RS-1 has LEDs. Both locos run perfect other than the light problem. My system is a Digitrax Super Chief. The light function works normal for all my other locos. If any of you have experienced this problem, please advise as to what the problem could be. Many thanks for any info you can supply.