TMCC novice......K Line 25303(edited) black Bonnet help?

I can't help specifically with your problems, but if you have the original boxes, those that might be able to help always ask for the product number.  Based on the title of your thread, it should start with a "K" followed by some numbers which might also be followed by some letters.

Chuck

You need to use the tether if the trailing A has motors. Most K-Line AA sets use a single motor driver for all four motors. To be sure place the trailing A on the track by itself and see if it moves on its own but I suspect the lights will come on and no movement.

As for the engine going into neutral when pressing the horn button, it may be due to the transformer momentarily cutting power as the button is pushed. If you have another transformer it would be worth it to try it.

Pete

I would tend to think that the powered unit will have to be connected to the trailing unit via the tether as I suspect all the control boards are in the powered A unit and they do need to talk to the motors (if there are any) in the trailing A.

The older transformers in some case would cause a quick power drop causing the engine to cycle it's direction.  The mechanical e units in older postwar trains seem less prone to this interruption.  To  answer your questions 100% correctly a product number as Chuck suggested would be helpful.

I suspect there is a mechanical volume control somewhere on the engine probably underneath.

Just turn the dummy over, if it has gears in the trucks, is is powered and MUST be tethered to the lead A-unit to run.

Thanks for the help so far! Here is the actual engine number K-25303. Just over $600.   Unfortunately for me the instructions cover a couple of other k-line engines/locomotives and says...you may not have this feature but doesn't say which piece they're talking about.

This loco has the TMCC modular system. Power link means the additional powered units must be connected to the A unit with a tether, like everyone else has said.

If you ant to add cruise, you need the Cruise Commander 'M' system.

The box says the A units are powered and the B unit is a dummy.

Thank you all if you are reading this!

It runs great. The horn works but sends the train to neutral- as expected- with the whistle lever dropping voltage. That must be what they mean when they say- some features may not work in the run mode (rather than program mode)   The "dummy" unit has a motor and light- but does not light up when separated from the front running unit. The underside has the holes for the program and sound switches but are empty. There is no visible volume control for the horn- I assume it would be on the remote which I am not planning to get right now. Without being plugged into each other, it's dragging the dummy car.

It does run very quiet!

I'll throw a video up here tomorrow