The MGA With An Attitude
SOLDERING SMALL WIRES - FG105
On 11/1/2012, Tim Lloyd in the UK wrote:
"Would you be able to tell me the best way to repair a broken wire between the coils"?
This is enameled copper wire (magnet wire). It is easy enough to solder, just finicky to handle with fat fingers or tweezers. Take a look at the schematic.
All three coils have one wire terminating on the "T" post. Wire from the left coil is strain relief wrapped on a plastic ear on the left coil, then strain relief wrapped on a plastic ear on the right coil before joining another wire (from right coil) in a common flag terminal to connect to the "T" post. You may be able to unwind one turn from the left coil to gain extra lead length, then solder the loose ends together.
This is hair size wire, 0.004" thick, and the insulation is unbelievably thin. Use a thermal couple temperature controlled soldering iron so it doesn't get too hot. Put a small dab of resin core solder on the tip of the iron so it melts. Poke a thin wire end into the molten solder for a second or two, and withdraw it, and it should be tinned with minimal amount of solder on the wire. The hot solder should melt the wire insulation and stick to the wire. Do the same for the second wire. Then wipe the solder off of the soldering iron as much as possible (onto a web sponge). Put the two wire ends together, overlapping a bit where the ends are tinned. Touch this with the soldering iron just enough to melt the solder, then draw away. The wire ends should cool in a second or two to be soldered together with very little solder.