Also, re-soldering the board will be done thoroughly. To quote the Virago guys...
Galvanic Corrosion
The space between unsealed connectors contains oil, moisture, fingerprints, dirt, ...etc. Also, being open to the world's contaminates, these things can seep and leach into the micro voids between the connector surfaces. Enter "Galvanic corrosion", where ionic interchange between disimilar metals acts like a corrosive battery, producing compounds that can interfere with good current flow, even making it act like a semiconductor diode. A good place for dielectric grease.
Inter metallic corrosion
Many brass and copper connectors are tin plated, and the fine border between those two dissimilar metals is closed to the outside elements. However, a strange long-term migration and intermixing of those metals occurs in that thin layer, leading to a form of inter metallic corrosion, which can also interfere with good current flow. Same can occur at the boundary of a substrate and a layer of solder, which can include boundary cracking of the solder. These types of degradation take many years to form, not an issue within normal life expectancy of typical vehicles. But, becomes real after 30 years or more.
We studied this back in the 80's, as part of determining the MTBF (Mean Time Before Failure) of various electronics products. These pictures represent similar biopsy-like micro cross-sections of tin plated copper-clad printed circuit boards.
What all this means, is that with the age of our bikes, electrical problems can occur which defy normal diagnostic expectations. For example, you could have a failed wire connector which still shows appropriate voltage, but won't deliver current to a device, like a light bulb. This was my experience three years ago with a failed turn signal bulb. The contact at the bulb base showed voltage, but the bulb wouldn't light up. Maddening. Traced it to inter metallic corrosion within the contact face. Cleaned up the face and re-tinned it, works fine...