If there is one good thing about the decoder in 1120’s tender blowing up right in front of Steve Stark’s eyes, which he brought all the way from Victoria so he could point them at Pembroke, it is that I get to replace the six wires between tender and engine. They may be 28- or 30-gauge wires, but they are too stiff, and any time I lifted the locomotive from the tracks, like when I cleaned its wheels a few hours before Steve Stark and other open house visitors witnessed the decoder’s demise, they took endless tweaking before all the wheels would maintain contact with the track.
Those connectors end in a pair of gubbins that, after hours of scouring the infinite catalogues at Digikey and Mouser, I learned are called “wire housings.” Once I learned the name that Mouser uses, I was able to find the exact part that Bachmann sticks at the end of their too-stiff wires. The parts themselves are inexpensive, but the shipping is a killer, even if you buy enough to do four locomotives!
These parts are the connectors in a Bachmann steam engine:
Pembroke:87 
We are all diesel modellers.
AH
Rene – TCS sell 4 and 6 pin connectors with flexible wire. Check their website and I’m sure Intercity may have them in stock. At least you’ll save shipping. You can also order direct from TCS or some other supplier.
Good to know, Jim. The trick is matching the headers on the back of the engine itself. That is why I’m happy to find the exact same part that Bachmann uses!