Frying decoders on Atlas Locomotives

[dieselfan04]

I am having trouble installing decoders in old style Atlas engines. I have installed 2 Digitrax DH163AO in a Atlas RS-3. One burned out immediately and the other ran for about 3 months and made a lot of motor noise when it ran.

Thinking that the trouble might be in the decoders, I switched to the NCE DA-SR decoder in a Atlas GP-40 with the Roco drive. When installing this decoder I placed electrical tape around the motor and when placed on the programing track it must have blown suddenly (was getting a short circuit). I replaced it with a Digitrax DH163D programed in the address and when placed on the main. A puff of smoke came out of the decoder and it was dead as well. 

I also have a Atlas S-2 with the NCE ATLS4-SR decoder and everything is running fine. I also run the Digitrax decoders in my Athearn diesels(can motors) with great success. 

Any help will be greatly appreciated!

 

[jeffrey-wimberly]

I don't have any Atlas locos to compare to but it sounds like you have a short from the motor to the frame somewhere. A hard wired decoder install is fairly straight-forward as the instructions tell what color wire goes where. The best thing to do is to verify exactly which wires went where and to check the locations with a multimeter to see if you're getting continuity from positive to ground. Continuity would mean a short in most cases.

[dieselfan04]

Thanks guys for the replies. The only place that the motor could be making contact is in the screws that hold the motors in. I did have to replace the screw on the S-2 with the supplied plastic screw and I'm thinking that this will help both of these. No where in the directions from either company did it say anything about replacing these screws. I will let you know if this helps.

[locoi1sa]

  I have never had to replace the motor hold down screws in the Atlas RS3/RSD4 or even the RS1 locos. I have 7 of them. Some are NCE DASR decoders and the rest are TCS A4x decoders. Could you have pinched the lower motor wire? Or could be the truck wires are crossed on one end. You said the RS unit made a lot of noise. Did it run on DC before decoding? How many amps did it draw? I bought a used RSD4 and had to replace the trucks because the bronze bushings were burnt and didnt conduct electricity very well. It was also noisy on DC and drew over 2 amps. New trucks from atlas and a TCS decoder and now its one of the best running loco in the fleet. At full throttle under load it draws less than 1/3 amp. Stall current tests should not be done. Put a train on it and find a hill to climb. 99% of the time the wheels would slip and not stall. Stalling a DC motor is a sure way of frieing it and a decoder.

    Pete