On the 21 pin connector, does it have pins sticking up? Or just holes? If holes, this is the dummy plug.Rather then pulling on it, try a small flat screw driver blade on one side to raise it a bit. Theb do the same on the other side. You may have to do this several times going from one side to the other.

 You can't disable dcc.

They should be 33".

Is this a dcc equiped tender?

Could be bad motor washers. There's one on each side of the motor. Go to the parts section and look up the GP40.

Maybe Evan Designs?

It should be an LED in the pole. So, polarity matters. If you wire the pole up aand it doesn't work, reverse the wires.

 It usually means dirty track , wheels or both. Could also be a bad connection to the decoder.

You'll need to remove the board installed from the factory. A Loksound 5 nano will have to be hard wired in. Loksound has a ge sound file, but it's for a 44 tonner. If you order, you have to have the file loaded into the decoder. Digitax has a N scale sdXn147ps. With this you need a pr3 or pr4 to down load a sound file. Digitrax has one for the  45tonner.

According to Soundtraxx, 10 light blinks means the deocder is getting too much voltage. Get a meter and measure the voltage at the track. Should not exceed 20 volts. There is no reset button. What power pack are you using?

 Hey Mr. Bach-man, any word on when the HO GE44 tonner with sound will be here?

 It looks like the cab roof comes off. Looks like a tab on each end holds it in place.
 https://www.bachmanntrains.com/home-usa/dwg/dwgs/H502X-IS001.PDF

No.

What brand DCC controller?

 No. The chasis for the FT-A is wider then the other 2. The GP30 is a split frame and had a triangle shape at the end. The GP7/9 frame is atraight across at the end.    Joe