Those black wires are a pain. Do I replace the entire wiring
harness on my 30 year old engine
or just solder new connections where necessary? I solder. I spread out strands and go at them with sand paper. Move them around a few times repeating the sanding
gets tbem pretty clean. I have a couple of Kester brand flux pencils of in my electrical
kit. These have the RMA type rosin flux dissolved in alcohol. You wipe the wires with the pen and the mixture flows onto the wire. Adds to what is in the solder.