# diesel stopping at turnout frogs at slow speeds



## [email protected] (Apr 7, 2016)

Hi All, 
Have a problem at my AF Turnouts at the frogs, when I run my passenegr Diesel through at slow speeds engine stalls out, are there any soultions? Using AF 720's / 720A turnouts.
Thanks


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## DonR (Oct 18, 2012)

First check the points. As I recall, they are powered
by touching
the stock rails. You may have lost electrical contact
and the points have no current. Cleaning the
points andstock rails where they touch may restore it.

Also, it's been many moons since running my AF train.
So I don't recall power pick up. You may have lost
pickup in one truck and that is causing the stops.

You can test both of these suggestions with a
multimeter.

To check the points, set the meter to AC and with
power to the track, set the points to divert. Put one probe on the Points, the
other on the opposite frog rail. If you don't get
a reading you have lost contact with the stock rail.
Try using your finger to press against the stock rail.
Do the same test with points set to straight.

To check the power pickup on a loco set the meter
to ohms. Put one probe on the front right wheel.
Touch the other probe on each right wheel. Any
wheel that doesn't get a reading is not picking up
power. As I recall the Tender picks up power for
some locos. Test it the same way.

If you don't have a meter you can use a typical
auto tail light bulb instead.

Don


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## [email protected] (Apr 7, 2016)

Thanks Don


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## AmFlyer (Mar 16, 2012)

The diesels should never stall in the turnouts. It would help to know what diesel. This is almost always caused by dirty pickup wheels. Take out the two small screws to remove the truck sideframes and completely clean each wheel. If they have traction tires there should be a sliding pickup in each truck sideframe. Make sure those are present and working. Reassemble and try it again. Since it is a slow speed problem only it is unlikely to be the turnout. See if it stalls when one wheel is on the plastic pointed frog. That indicates the other pickup wheel on that side is dirty.
Gilbert turnouts provide power to the movable points through sliding contacts inside the turnout. If the copper contacts are dirty they are easy to clean.


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## [email protected] (Apr 7, 2016)

Thanks for your reply Tom, appreciate it!


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## DonR (Oct 18, 2012)

The easy way to clean diesel loco wheels is to
place a paper towel wet with alcohol on the
track run the loco front truck onto the alcohol,
hold the loco from moving, and run up the power
a bit to spin the wheels. Then do the same with
the rear truck.

Don


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