Need help with PW 682

You got the brush wires correct. Check the green wire to the field for a good soldier connection. Slight stalling I would check the center rail pick up to the e unit and also look for a problem with e unit grounding. 

Thanks, will check the grounding, didnt think of that

A few thoughts:

Check you solder joints.

Double check that your new e-unit is good.

Your replacement could have a bad solder joint, or a contact problem between the fingers and the drum. I had this happen on a loco I was recently repairing. In this case, the joint looked good, but would not conduct electricity. It was the connection between one of the contact fingers and it's lead wire.

How about the motor? - Is the commutator, brushes, springs, and brush holders clean?

Is your issue a loss of power or binding?

Sometimes the backs of the wheels will rub against the locomotive frame causing a bind. This is often worse when the loco goes into curves.

C W Burfle posted:

A few thoughts:

Check you solder joints.

Double check that your new e-unit is good.

Your replacement could have a bad solder joint, or a contact problem between the fingers and the drum. I had this happen on a loco I was recently repairing. In this case, the joint looked good, but would not conduct electricity. It was the connection between one of the contact fingers and it's lead wire.

How about the motor? - Is the commutator, brushes, springs, and brush holders clean?

Is your issue a loss of power or binding?

Sometimes the backs of the wheels will rub against the locomotive frame causing a bind. This is often worse when the loco goes into curves.

I had a heck of a time with a 681 until I realized that one of the brush connections was shorting ever so lightly against the boiler casting. 

See if yours runs OK with the boiler removed.

I've had similar problems that PLCPROF noted. Sometimes the solder connections on the e-unit (especially where the "hot" wire attaches from the rollers) stick out too far and short on the shell. Bending the contact inward, reducing the amount of solder, or electrical tape on the inside of the shell on that spot eliminates it.

Roger

It runs the same with the boiler shell off.  am checking the solder joints later this evening.  the unit worked fine until I put the new e-unit in

In my 60+ years of running PW trains, I learned the hard way that a PW 682 runs the best when using at least .042" or even better .054/.072" curved track.  When run on  standard .031" "O" ga the 8 drive wheels can bind on the tight curves.  I have 2, 682's that I run only on .054" curves. Never have a problem.  Just something else to try, JMHO.

Bob