Soldering is very easy. Knowing a few simple facts will make you a pro instantly.

1. Get around a 35Watt soldering iron is best for most automotive soldering applications. It will heat up connectors, posts, and wires enough for a good flux of the solder. A soldering gun will work, but are harder to handle when working with smaller parts, and they get real hot real quick, forcing you to remove the gun or melt any plastics nearby. It can be done with practice, but don't try one on your first project. In contrast, a 20Watt soldering iron may not heat up larger wires or connections enough to get the solder to flow.

2. In the previous point, I alluded to the fact that heating the object you are soldering is important. Increasing the heat transfer increases the ability of the solder to adhere to the connecting parts. To greatly improve heat transfer, use soldering paste. Soldering paste makes a world of a difference. Dip wires into it and smear it on connectors and posts before applying the soldering iron or gun.

3. Solder. Use flux-filler solder wire. Also known as resin-core or acid-core solder wire.

4. Get the parts lined up before-hand. This includes having a good mechanical connection. You do not want to have to fiddle with a stubborn wire with one hand while trying to hold down both the switch and soldering iron with the other. In the case of the moonroof switch, I cut about 1/2 inch off the wire I was about to solder, dipped it in soldering paste, wrapped it around the post that I had already smeared with soldering paste, and ensured the wire had a good mechanical connection so that it held itself onto the post.

5. Use fresh solder. Once the iron is at temperature and you are ready to solder, clean off the soldering tip quickly (I use an organic-cell sponge that is damp. I cut the bottom off a plastic bottle and cut the sponge to fit inside it), then apply new solder to it and put it right on the wire, so that the "blob" of melted solder is between the wire and soldering tip. Use the soldering gun to press the wire against the pole. Once the blob of solder begins to move into the wire, begin adding new solder to the where there is already melted solder flowing into it. You will find that other points may not be hot enough to melt the fresh solder.

6. Ensure an electrical connection. It is easy to tell when the proper electrical connection has been made at a wire/post connection. When the post is hot enough the solder will flow from the wire onto the post easily. If the post is not hot enough and you have filled the wire well, the solder will bead around the post, much like water beading on a freshly-waxed car. This tells you you need to get more heat to the post. Try getting the soldering iron onto the post itself while maintaining a connection with the melted solder around the wire. To heat the post and allow the wire to cool would not be very fruitful. And by cool, I mean it only takes a few seconds for the solder to cool enough to soldify, although it is still very hot and will burn you good. Try more paste if you are really having difficulties.

7. Is it a good connection? When a proper solder job has been performed, the solder has a smooth transition from one object (wire) to the next (post). It should not look like it is trying to avoid the post by ballooning around the edges of the wire where it meets the post. The solder should fill the wire enough to make it look like a single siver strand, and it should coat the post entirely in the vicinity of the wire. If there is too much solder, you can reheat the connection with the iron and tap it while upside down to get the excess to fall off (don't do this over your new kitchen table!!!), or you can use solder removal wire or a "solder sucker" (marker-sized device that creates a suction at it's tip to suck up melted solder). Frankly, this is not a mil-spec job and a big blob won't hurt, as long as it is not so bog that it reached over to another post!

I'll get images up as soon as I can.