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Walthers ML SD70 Engine Issues

HO enthusiast Matt sent in this question:

I have a Walthers ML SD70 that runs almost perfect around my track. Just purchased 2 Scale Trains and 2 Athearn SD40-2’s. All 4 stutter or just don’t go at all. I made a small round test track that I could get them all to work after a few min with help nudging them along and would run fine. put them on my long track even with 2 power points in the middle and nothing again. “

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12 Responses to Walthers ML SD70 Engine Issues

  • Robert Johnstonsays:

    It sounds to me that you need to make use of more feed lines to your track. I like to go no further than 6 feet, 2 meters between feeds,

  • phil johnsonsays:

    check electrical continuity around the layout. most times you have a loose rail joiner. I’d also take a Bright Boy to the rails. Athearn and Walthers ML are not that particular but Scale Trains are. Robert’s right you may need more feeder or solder rail joints

  • Robertsays:

    If 1 loco runs OK on the layout and your other ones don’t, it looks to me that if these are second hand then they could have dirty wheels/pickups or the motors need a clean and lube. Turn the locos up side down and touch the wheels with 2 wires directly from your power supply. Do they still behave the same way?

  • Franksays:

    Maybe your controller isn’t it enough.

  • Kevin Wilsonsays:

    Check track voltage with a multimeter , then check output from controller. Are engines DC or DCC ?

  • Craig Inghamsays:

    Two strong possibilities. 1 Clean the rail with a Brite Boy type device and 2 clean the wheels(tires) also. Is the rail brass or nickel-silver?
    If this has no benefit, place each engine upside down and apply voltage directly to to the wheels and note quality of operation.
    Al this is assuming there are no electrical wiring problems within the engine. Good luck.

  • mattsays:

    I have cleaned the track, wheels, contacts. All are brand new engines. I do need more feeders, but I am currently just running EZ Track on the floor till I get the permanent layout built. I have a NCE starter kit and have wondered if it is lacking the power. Plan on eventually doing the wireless controller, since the layout will be around the ceiling. I was going to wait on that because of the cost but thought about getting it to see if the 5 amp power helped. So it could just be the track, but seems weird that one engine runs with little to no issues with sound and everything, but the other 4 won’t make it 3 ft without stopping.

  • Bob Rimmsays:

    Over the years I have built several HO, 027 and 0 Gauge layouts and they all seem to have the same issues. There are weak spots in very layout and they are always the track connectors. The rules that I use on all three scales is to: 1) Have multiple power connections from the power pack to the tracks. 2) Always have power to all three sides of a switch. The problems are usually due to the design and construction of the switches. 3) The track clips get loose over time if the tracks are constantly disconnected and reconnected or they are not making a clean solid connection beween the two rails. The last possability is that there is a wiring issue on a connection. An inexpensive volt ohm meter either analog or digital comes in very handy for trouble shooting the problem. Lastly look for a short accross the rails.

  • Constantin MGGL De Bocksays:

    Everybody has the right idea. You have to much resistance in your train circuit. One locomotive works fine with your power source but four locomotives are probably drawing to much power. Maybe the power source cannot give enough amperage( check this out first before anything else). on the other hand it could be to much resistance in your feeder lines. you need to check your feeder lines the tracks, solder connections. To do that; put a resistance like a high wattage light source attached to the tracks and measure voltage across the tracks and any other connection. You should measure to full voltage and power over the tracks and nothing over connection or section of feeder line. I hope this helps you to sort out you problem.

  • Norman Chippssays:

    Could be power if you are running one and OK. if all four are on the track at the same time remember if they are DC each engine takes about 1 amp and if your power pack only delivers 1 amp your voltage will be low. Check the voltage with a meter.

  • Herveysays:

    Since one loco runs ok then your problem is likely pickup on the other four locos. This can be influenced by the track. You are using EZ Track, nickel silver or steel? Oxidation on the track will give you this problem and is likely to occur with steel track (black road bed). It will occur with nickel silver but is less likely.
    Check the wheels to make sure they are clean and pay attention to the back of the wheels to ensure the wipers are not filled with gunk.
    There are ways of adding more pickups to increase reliable conductivity but unless you are very comfortable with that type of work then you are better to leave that to the professionals.

  • David Stokessays:

    With a new loco on he roster the following tune up actions are essential
    1. Is it DC or DCC, and which do you use to control the layout? – stupid question I know, but so many
    people by a new loco, put it on the track, wind up the juice and either Pufff, or nada.
    2. Check the wheel gauge and wheel back-to-back and correct if necessary
    3. Check the coupler height/operation. A loco that can’t pull our train aint much use.
    4. Check the flow path of power from wheels to motor – use a multimeter, get one if you don’t have one
    5. Are the wheels clean? If not clean them
    6. Put the loco on the track, turn up the controller and it should now run, except if you have more
    than 3 locos pulling juice at the same – each one will draw X amps – if more amps are used than
    your controller can deliver then nothing will move.

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