One of my Bachmann 2-8-0's is giving me difficulty. 2 female-ended plug wires coming from the tender, and plug into the small circuit board in the "firebox" bottom. One is 2-pin, the other is 4-pin. The 2-pin male on the circuit board snapped off the board when I was removing the wire.

My question is, when I solder this back to the board, does it hurt for the solder to touch on the other side of the board (opposite side from where the male plugs are located)? I don't have a lot of experience with electronics to know. If I had to guess, I'd say it would short out. How do I keep the two solder puddles from touching? Petroleum jelly maybe? Any insight is greatly appreciated.