Is the 3000 the only loco that stops? Maybe it has nothing to do with the pickup shoe. When it stops try to connect the puffers with a cable from ground. It might start running.

I have three locos on the layout: br86, br74, and br89. The br74 rarely has an issue. The br86 will fairly often cause a spark and an associated high pitch noise that happens when the track is shorted. This happens regardless which direction it is entering the turnout, but more often happens when entering the end of the turnout closest to the lantern. Both the br86 and br74 are digital converted and have 60982 decoders with permanent magnet motors.

The 3000 usually won't spark but very regularly will just stop in the middle of the turnout. If I gently push it to one side to help its outside set of wheels contact the track for a better electrical connection it will run fine. I've tried widening the gauge but that causes the loco to derail. Sometimes though it seems to trip something in the decoder which makes the loco stop and won't run again unless I shut off power to the track.

The 3000 didn't do this to this degree before I converted it to digital. It used to be Delta and ran mostly fine over the turnouts. I'm wondering if part of the problem is the 60760 decoder. I've read about an alzeimers capacitor (?) which may help here. I'm not sure.

But now that the locos all have permanent magnets, I am running them at a much lower speed so that may be part of what's happening.

But back to the br86, it does spark on the turnouts quite often, which leads me to believe the turnouts are the problem. The rest of the track is fine, no issues there. I have tried experimenting with the gauge on the br86, but the design of its center drive wheels may be part of the issue.

I cleaned the turnout rails, first with isopropyl alcohol, then a rubber eraser, then again with alcohol. It didn't seem to help

Hi Brian
I have used a lot M Tracks and they are excellent provided in good condition (metal ballast not bent, joiners "refurbished")
Here are a few things to consider
- shorts are not caused by the slider but rather by wheels touching the "long" studs nearby. This can be caused by (a) improper spacing between wheel (13.9 mm) or by "weak" metal counter rails
- current fails are caused by used, non-flat or non-Märklin sliders.

With ANY 50 mm long-slider, it is NOT normal to have any current interruptions

How to adjust metal counter rails?
- access underneath the point (remove the base plate)
- position the counter rails by using a reference axle (13.9mm spacing between innerside of wheels)
- with a long-nose-plyer twist gently the extremity of the counter-rail (made of sheet metal) until it is fixed (made sturdy with the rails body)
- finished

Just my 2 cents. Cheers
Jean