Rear Truck Roller on MTH Imperial Desiel does not pass power: 30-20749-1 BNSF ES 44AC

Wire probably came off the pickup roller. Should be an easy fix.

Ed, the MTH engines are  really NO different inside then Lionel, Williams, etc.  the  4, or 6 screws hold the shell on the frame.  If the roller wire is off or loose, you'll see it right away.  SHould be red, but sometimes they are black.. 1 goes to the frame, one to the motores or the control module....

Once apert. if you have trouble, take some photos of the insides.. so we can see what's going on.....

Agree with Lou ,Ed.

Before you remove the shell , take your volt /ohm meter and see if there is continuity between the front ant rear pickups.

I just opened up a new Premier F7 .        I like to take a few pictures with my phone after removing the shell.         

            I like to slightly distress the front and rear screws connected to the trucks ( black wire  ) and the center pickups ( red wire ).  It helps when screwing them in to remove the paint that might be  in the  holes and since the screws are sometimes found to not to be tight, the the distressing makes a very snug fit.    I've read somewhere on the forum that MTH engines are prone to poor grounds.     

    WELL ........to my surprise I found the screw on  connector for the three ground wires rolling around inside the frame and the three bare connected wires loose under the board . 😨   This was a brand new engine.

Be vert careful when reassembling the shell Ed.   Make sure that you are not going to pinch any wires.       I like to also take a few pictures with my phone when I first remove the shell.

Check the red wires tied with a wire nut near the board and check continuity between the rear pickup and the wires bundled under the wire nut.  If open, the wire may have broken under the heat shrink at the ring terminal connected at the pickup.

Dallas/Jon, to my surprise there is continuity between front and rear rollers.  I opened it up and didn't see anything out of the ordinary, loose, disconnected. I put ti back together.  I ran my Bush 4141 again and it too stops at that switch and that switch only. It must be running at or more than 20 mph to make it through the switch. I then tried the BNSF again and it made it through that switch because it took off like a rocket!  I had to cut power to the track to stop it, or change direction. I did a feature reset. Same result, then a factory reset, same result. I guess I must have screwed up something.  Is it time to take to a tech?  

If you have several switches and no problem at any except this one , I would say the distance between the pick ups in relation to the switch just might be the problem.

You mentioned that a higher speed going through the switch didn't shut the engine down.

I had two Railking Dash8s  ( longer engines ) that I changed the pickups on to change the distance between them . The one engine went through OK but the other still shut down unless I ran through the switch at a higher speed.

After seeing issues like this on the forum ,I took some advice and inserted a very short piece of track between my two switches and the problem was gone.       At that time I had 4 continuous switches with MTH Realtrak .    

Might be an issue with the switch positioning Ed.  🤔  I'm not familiar with FASTRACK switches. 😶

Dallas, I did think about extending the middle rail in the switch just a tad to see if that helps but I'm to the point that it just isn't worth the trouble. Now that the engine's speed is uncontrollable, I've managed to take an engine that was running well and screwed it up because of that switch issue.  Oh well, that's why there are Hobby Shops with folks that know what they are doing.   Thanks for your help.

Jon, I have continuity between the front and rear rollers.  I put it back up on test rollers again and this time the rear truck roller provided power. I don't know if I jiggled something just opening the shell or more probably I didn't have it seated properly on the test rollers the first time I tried it.  As I mentioned to Dallas, I've now screwed up the tach, I believe and that's why speed is now uncontrollable.  I've managed to make this the perfect DIY project! 

Start it up on a good piece of track tomorrow .  Sometimes the logic gets screwed up and gets it straightened out after a " time out ".  😪

Maybe afterwards you could try a conventional factory reset .  Maybe one of the tech wizards will chime in.

Maybe tomorrow you will have an idea.

Don't despair ......this is your opportunity for excellence. 

@Quarter Gauger 48 posted:

Ed, the MTH engines are  really NO different inside then Lionel, Williams, etc.  the  4, or 6 screws hold the shell on the frame.  If the roller wire is off or loose, you'll see it right away.  SHould be red, but sometimes they are black.. 1 goes to the frame, one to the motores or the control module....

Once apert. if you have trouble, take some photos of the insides.. so we can see what's going on.....

QG48's idea of the photo of the insides is a great way to start.🤓

Good that both rollers are working.

Well, because I think I screwed something else up, the engine is off to the LHS for tender loving care.  I love DIY.