Premier Niagara electrical connection problem.

Yes the receptacle on the engine side needs to be inspected for broken connector or bent pins.  Tether can be replaced too.  But you have not given the model number.  Not sure how coming out causes short.  Usually just causes shutdown or lose of some functions depending how far out it comes.  G

Thanks for your response GGG.

The model number is 20-3047-1   I'm probably using the wrong term for "shorting-out".  If the plug in the boiler cap moves at all the engine shuts down...into neutral mode and will not respond to forward or reverse commands.  I've tried to reset it to factory defaults by hitting the whistle button once and the bell button five times on the transformer...but no response.

The NIA model has the board in the engine and the tender only has sounds, battery.  If the engine was moving and the tether came out engine should still run but sounds go away.  Since you're operating conventionally, once the engine was stopped or hit a dead area and loses power you cannot get it to move again since it needs the battery for conventional operation.  It would light up and smoke just no sounds or motion with tether out.  Make sure you have a good battery that is full charged.  Inspect plug to engine not damaged, inspect 10 pins to ensure not bent.  But if plug keeps falling out you need to take shell of engine and inspect the PCB plug receptacle for damage.  G

Thank you for your explanation.

I've experienced all the symptoms you have described.  I took the tender shell off and inspected the tether connections (OK).  The right-angle tether plug is suspect.  I tried to get the boiler shell off but only succeeded in getting it halfway off...too much wiring balled up and jammed into the boiler shell. The receptacle pins look straight, but the receptacle appears it might be too recessed to completely receive the tether plug.

I was able to reset the engine to factory defaults, but the engine still won't go into forward or reverse. I have a BCR installed instead of a battery and it registers 100% charged.

At this point I'm seriously considering finding a Williams reversing unit for steam locomotives with whistle/bell and replacing the whole PS2 unit.

Tether can have a bad wire or you have broken solder joints on the engine side PCB pins.  G

Guess I'll go ahead and replace the tether plug and the plug receptacle. I have a small/light soldering iron for circuit-board work.

Is there a special technique for removing the boiler shell (other than the 5 screws described in the manual)? I already broke off a detail part the last time I tried to remove the shell...used epoxy to glue it back on.

According to the MTH parts list for the 20-3047-1 Niagara the 90 degree, 10-position tether is BC1000002 and the 10-position receptacle is

AG0000039.  Worst case scenario it ends up as a nice display engine.

Does BC0000217

Take the place of BC1000002

I'd rather not have to solder 10 tiny wires if there is a work-around.

If your tender has the tether plugged into a mating connector, then the BC0000217 is what you need.  However, if there is no internal 10-pin connector, the only choice is to splice the ten wires of the BC1000002 to the existing wiring.  Basically, you have to already have the BC0000217 if you want to replace it with one.

You want BC1000002 since your board is in the engine. G

Tether and plug on the left appear to be damaged.  Tether and plug on the right is the new BC1000002.

How much old tether length do I need for attaching the new BC1000002?

Thank you for all your help/advice in this matter!!!

See how long the original tether is? Well the replacement has to be the same length, or a little longer for slack.  #1 rule is cannot be shorter.

Just solder it right on the PCB.  Matching colors. G

In case you need to get into the engine.