I do just like Tom has suggested. Many times people try to solder with the soldering tip being too cold. With a cold tip you have to hold the soldering tip to the wire too long and that transfers the heat to the insulation and melts it.
Try tinning the pad and the wires first, then with a hot tip you should just have to touch the wire to the pad for a second or two. If you have to hold the tip on the wire longer than that, the tip is not hot enough.
I do this for the orange and gray wires as well has the yellow, blue and black.
Paul,
Solder the orange & gray motor wires first then leave them long on the decoder side. I would do the same for the red & black track wires and the white, yellow, and blue (common) lighting wires. Once you find that everything works properly, unsolder the wires from the decoder ONLY, cut them to length (with adequate slack - especially for the track wires), then resolder them to the decoder.
If you are melting wires while soldering: 1) your soldering tip may be dull, 2) your heat is too low, or 3) both. Your tip needs to be shiny to properly transfer the heat and melt the solder. For soldering 30 AWG wires to decoders, 650-700 degrees is quite adequate.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
This is a general question/problem.
The TCSDCC instructions online say to leave the wires long and then test the engine. Once all is well, "tighten" the wires, i.e., take out the slack. They show nice pictures of this. The long wires are soldered and then would need to be unsoldered, cut, and then resoldered. This would mean running the risk of melting sonething. The gray and orange wires to the motor would be especially difficult.
Has someone in the forum have a suggestion for accoplishing this correctly? My inclination would be to carefully cut the wires the right lengths the first time. What does the forum say?