Trouble-shooting a balky loco/turnout combination

[chuck geiger]

Need some help? I have an issue with a turnout and the pre-owned NW2 Kato unit. So it runs great through all the turnouts now down on the layout, except one. The track is clean and it runs through all of the other turnouts without an issue at a low speed, but this one:



I have used these turnouts with no issues in the past. Atlas C-55 #5 and #7. It's just this one and I can't see anything wrong with it. I read "power the frog" which is not going to happen with my low electronics skill set and then read short wheel base loco like the NW2. Again runs through all of the others with no issues.

[John]

where does it stop .. and does it stop there all the time .. can you highlight the point where it stops?

do you have a multimeter?

do any other locomotives have a problem?

[chuck geiger]

It stops on the frogs on both sides of the pictured turnout. Pre owned and haven't cleaned the wheels, but it runs through all of the other turnouts as slow speed fine. If it runs at higher speed it goes through with a slight shutter. The GP-9 was better on the same area, but still the same really. No I don't have a meter. I will use Sally's clipper oil on the rails after a real good cleaning on both turnout and the loco. Weird issue. All locos good at slow speeds through all of the other turnouts.

[nickelplate759]

Leaving aside the dead frog, check continuity of the rails that are in between the frog and the points to their respective outside rails.  I'll bet at least one is dead.

It's also possible that one or both of the rails on the far side of the frog (closest to your switcher) are dead.   In both cases there are jumpers embedded in the ties that link those rails to the outside rails.  You can't fix that jumper very easily (it's embedded in plastic), but you can add another jumper of your own - that should address the problem.  I've had to do this several times.  I run the jumper between the ties and hide it (eventually) with ballast.

[davefoxx]

I’d bet money that one or both of the points aren’t getting power.  I saw that on my old N scale layout.  Some four-axle power would stutter or stall through there when one truck was on the frog and the other truck was on the points.  I actually soldered jumpers to the points.  That and Frog Juicers.  Fixed.

Hope this helps,
DFF

[jdcolombo]

Clean the wheels, even if it runs fine through your other turnouts.

But, as others have pointed out, check continuity on the point rails and the outside rails.  The moveable points, in particular, are prone to electrical problems due to the design of the "hinge" on the Atlas switches.  But sometimes the rails beyond the point hinge up to the frog lose power, as well. 

John C.

[chuck geiger]

As soon as the rear wheels clear the frog, the NW2 runs fine...front wheels stop past frog, then stall, push it past frog and it runs.

[chuck geiger]

As always you guys are the best. I think it's the hidden factory jumpers/connections failing.

[peteski]

Does it stall when on the other route through the turnout, or just one one route?

To me it seems like a case of one truck not picking up power, and a dead piece of track in the turnout.  If it is a DC loco, or DC operation is enabled in the decoder, I would take a 9V battery and touch it to each wheelset to see if they all pick up power.

I would also recommend wheel cleaning (always good to start with that procedure).

In these locos, it is really easy to misalign the pickup strips, which causes intermittent pickup issues.  That's because the strips are free to slide forward and back.


The green arrow points to a properly installed strip, and red points to a misaligned strip.

[woodchip]

Buy a affordable multi meter. You’ll have it forever and in a situation like this you can quickly determine where you do and don’t have power.

[peteski]

Buy a affordable multi meter. You’ll have it forever and in a situation like this you can quickly determine where you do and don’t have power.

Preach it Woodchop, preach it brother!
Since model train hobby involves dealing with electricity, a multimeter is one of those indispensable tools every model railroader should own.   Hopefully Chuck already has one.  If not, there are many digital multimeters available for less than $20.

[nkalanaga]

A multimeter is nice, but an ordinary 12-volt light bulb, the once-common grain-of-wheat type, will work just as well for dead track.  Turn the power on, and touch the leads to the various rails.

It won't help you find a short, but for stalling locos it works fine.

[NtheBasement]

Another possibility is your trackwork is not flat and wheels are slightly lifted off the rail.  Lay a steel ruler across the top and look for gaps underneath.  Some locos have tighter trucks than others - loosen the screws that hold the frames together about 1/8 turn.

[chuck geiger]

Thank you for all the suggestions, when we head back down next month - I am well armed with possible fixes. HAPPY NEW YEAR.

[Memster1]

It looks as if the points are not in full contact the the rails, and that "might" cause the power drop.