Tam Valley turnout control


I'm starting with the single turnout controller boards.

When I first hooked this up, the units drew 30 - 40 milliamperes when on.

After my first "auto align" the switch would throw, and then sit and buzz in the thrown postion for a while, consuming almost a 1/3 of an amp. If you get the auto align working, then it will eventually settle down to 4-8 milliamps. These currents are WAY too high for Z scale.

I had all kinds of difficulties. This page is still being refined.


reset to factory defaults:  (you will find out why I put this first!)

  • power off
  • hold down both buttons
  • power on
  • The leds blink for a bit and then stop

When in doubt, start over and reset the decoder. If it is really weird, reset and leave unpowered for a while. Don't ask me how I know this!

Exceptions and omissions to the manual

First: READ the manual, and see how to push the buttons, it's still very misleading to me now, see my technique below.


The reset command does not move the servo to dead center, but it gives some small difference between endpoints.

Looking at the top of the servo, PB1 goes left of center, PB2 goes right of center.

Pay close attention to centering the switch before doing the auto endpoint settings. I personally have had very poor experience with this even with reducing the "hold current" I recommend manually setting the endpoints.

After installation, cycle the servo back and forth several times. If you hear the servo "buzz" at an endpoint, back that endpoint back towards center.

Monitor the current after setting. Over 8 ma, you are still stressing the decoder servo (and probably the switch)

Use the "program accessories" mode to set cv's in the decoder, program track and POM don't seem to work.

I strongly recommend putting the lock jumper on the board whenever you are through, you really don't want to accidentally reprogram the decoder by someone fat fingering the buttons.

Board labelling

board labelling can be confusing!

The servo connects to the board near a 2 pin jumper that has RMT.. the servo pins say BRS, for Black, Red, Signal (usually white)

The relay board has the same BRS markings, but the servo board has no letters, just a triangle, the signal, or white wire goes there

My Installation technique


First I mound the servo in the mount, and put a simple single arm on the servo.

One really annoying thing is that after auto align, the switch throws, and then sits and buzzes in the thrown postion for a while, consuming almost a 1/3 of an amp. If you get the auto align working, then it will eventually settle down to 60 milliamps.

DCC programming

First you will want to set the DCC address. Make sure the programming lock jumper is removed.

Then press both buttons for a second, both LEDs blink

Now send an open or closed accessory command, making sure you use the "sense" of the turnout position, since this also sets the open/closed setting too.

Now to set other parameters, you use the program accessories commands for POM.

Indicator lights

I got a bit confused with the dual LEDs, because you don't easily know which LED is which. If you don't have the LEDs clearly marked for the main and diverging routes, then you might do what I did, program the leds so BOTH are green for straight through and BOTH are red for diverging. With this setting and also the "programming lock" jumper in place, you can protect yourself from people who don't "know" your layout, or those who just are't too whopee on this stuff.

This way it's all red or green. Just set CV's 40=1, 41=2, which reverses LED2 to match LED1 (this assumes your installation has not required a "reverse direction" CV change.


Weather Underground PWS KCACARLS78