Hello,
I have an MTH RailKing 30-1667-1 Great Northern Mallet 2-8-8-2, with PS 3.0, bought on ebay. The tender coupler opens autonomously, even without any cars attached, after the engine runs a couple of feet.
Does anyone have a suggestion for locking the coupler in the closed position? I have reset the PS system, but this makes no difference -- the coupler still pops open.
Many thanks,
Doug
Replies sorted oldest to newest
Unplug the coupler. If it still is opening- it's a mechanical defect in the coupler.
Worst case, replace it.
https://www.mthpartsandsales.com/shop/search
| DD0000032 | PROTO-COUPLER / LONG / 51mm OVERALL / PS 2 & PS 3 |
| DD0000033 | PROTO-COUPLER / SHORT / 44mm OVERALL / PS 2 & PS 3 |
Thanks. Before I open the tender, let me ask whether there is a way to do this without removing the shell.
STOP RUNNING IT UNTIL IT'S ADDRESSED!
When the coupler is opening like that regularly, it's frequently a short in the wiring. Continued use will damage the PS/3 board, something I'm sure you'd like to avoid!
It will have to come open to track this down.
Good catch, should have said that, hoping it's not that kind of a failure (pinched wire or short to frame).
Thanks! One of the gray solderless connectors had come off, with the twisted wires in position to make intermittent contact with the shell. Restoring the cap seems to have solved the problem -- two complete laps now without the coupler opening.
In case the problem returns, let me ask whether the PS board can be damaged by operating without the coupler plugged in.
Doug
@Doug Troeger posted:Thanks! One of the gray solderless connectors had come off, with the twisted wires in position to make intermittent contact with the shell. Restoring the cap seems to have solved the problem -- two complete laps now without the coupler opening.
In case the problem returns, let me ask whether the PS board can be damaged by operating without the coupler plugged in.
Doug
To my knowledge there is no warning or bulletin on PS3 Steam electrocoupler must be plugged in or fitted with dummy resistor.
That information only applied to the Diesel/Electric PS3 style board. Again, PS3 Steam is a different animal- different board, different wiring, different connectors (30 pin VS 40 pin) at the board.
The problem did come back, even though I find no other sign of a possible short inside the shell. So I've unplugged the coupler, and everything again seems to be fine.
There may be a chance for a short to occur at the point where the wires attach to the coupler, outside the shell: there is a small piece of transparent plastic, apparently designed to keep the solder joints away from the axle, and this had slid forward. I am running O31 curves (for now, as I like to say), and so the couplers move around quite a bit.
With your last note, however, I'll continue with the coupler unplugged.
Many thanks to both of you!
Doug
Access to this requires an OGR Forum Supporting Membership
