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Repairing crumbled switch and light bulb socket soldering.

Some of the older Kawasaki's, and possibly the other brands of motorcycles may be experiancing crumbled or failed switch and light bulb factory soldering jobs. Here's a repair procedure:

When repairing soldered wires on motorcycle switches or light bulbs sockets, have the following on hand:

1. A 25 Watt soldering iron or one that the wattage can be adjusted.

2. Rosin core solder.

3. Rosin flux or soldering paste (Never use solder or soldering paste designed for plumbing work, as it contains an acid that will corrode the electrical joint, ruining it).

4. 91% rubbing Alcohol, or 70%. The lower percentage will clean up flux residue, but not as good as the higher percentage stuff. Acetone will also remove soldered flux residue, but it’s flamable(easy to ignite).

5. A cut down ½” paint brush, or acid brush for scrubbing the repaired solder joint.

6. Clean rags or paper towels.

7. A damp sponge to keep the soldering iron tip clean.

8. Some “Solder Wick” a braided bare copper wire designed to collect heated excess solder, aiding in joint preperation, available at electronic supply stores.

9. Some wooden toothpicks.

10. Small Hemostats or clip on heatsinks.

A. Before soldering, “Tin” the soldering iron tip by plugging it in or turning the iron on, allowing it to get to operating temperature(2-3 minutes).

B. Unroll about 3” of solder from the roll of rosin core solder & then using a clean rag or paper towel moistened with Alcohol, wipe the unrolled solder, removing the finger print oils that will create a poor solder joint.

C. Apply a small amount of solder to the now heated soldering iron tip, wiping the excess off with the wet sponge or rag, keeping a thin layer of solder on the soldering iron.

D. The soldering iron is now ready for use, but before applying the heated tip to a wire, wipe the tip on the damp sponge or rag, this removes any oxidized solder and makes for a much better connection.

E. If the joint to be repaired is grey in color or appears “Crumbled”, apply some rosin soldering paste or flux to the joint with a small toothpick of screwdriver, and then apply the soldering iron tip for a few seconds.

G. The fluxed joint should clean up, allowing for a better connection. If no luck, use the solder wick to remove all traces of the old solder by apply in it between the soldering iron tip and the bad joint.

H. Hemostats and clip on heatsinks will be used to prevent the wire insulation from burning, overheating & pulling away from the connection.

I. Apply a small amount of flux to the joint to be repaired & then a very short duration of heated soldering iron tip & solder(like a few seconds or so).

J. Clean off the repaired joint with the brush & rubbing Alcohol, the newly repaired joint should appear clean and bright, almost as if it were polished, with no voids or holes.

This comes from my years at General Dynamics/Convair (1983-1993)
When I built, wired and assembled test equipment and electrical cables for the Tomahawk and later the Advanced Cruise missile.

The company had a week long soldering school, instructing you how to hand solder to Mil-Specs.
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