I ran into problems soldering. I was using a Coleman ColdHeat soldering iron, and some old solder I found laying around. In addition, I needed a conical tip for my ColdHeat, and didn't have one. And I inadvertently cut through the actual power wire leading to the 4 and 1. I ended up twisting the tiny LED wires (Two..one for the front LEDs and one for the rear LED's) together and inserting them along with 1/2 of the 4 and 1 power wire into one end of a Radio Shack bullet connector, and inserting the other half of the 4 and 1 power wire into the other end, then crimping both ends of the bullet connector to securely hold all wires in place. Works fine.