The connectors overheat due to corrosion in the connector plug contact surfaces.
The two pieces of metal inside the connectors only allow for a small surface area in making the connection. In clean condition, there is just enough contact surface area to handle the electrical load.
If the contact area shrinks due to corrosion, then the same amount of electricity that was going through a larger contact area is now being forced to go through a smaller contact area. A byproduct of this is heat. This heat fosters more corrosion - which further reduces the contact surface area - which causes more heat - a Catch-22.
Eventually the connections heat up so much that they melt and cause issues.
It has been recommended to do this once a year, or twice a year if commuting in a place where they regularly salt the roads in the winter.
- Disconnect the connector
- Spritz with contact cleaner
- Spritz with silicone spray
Tools and supplies
- Contact cleaner
- Pencil eraser and/or 320/400 grit sandpaper
- Needle-nose pliers
- Thingie to disassemble the connector--anything that will slip into the connector and depress the metal "catch" so you can slip the connector out
- Small awl
- Tweezers from a Swiss Army knife
- Really small screwdriver
Special thingie ("Terminal Extraction Tool") sold by various websites
Carefully take apart each connector and spray the dirt out with the contact cleaner.
Remove each wire from the connector, clean the male blade connector with the eraser and the wash off with the contact cleaner. Only remove and clean one wire at a time. That way you won't forget where it goes back.
Very carefully tighten the curl on the edges of the female connector. If there is any corrosion clean it out with a small piece of 300 grit sandpaper. The corrosion in the blade connectors is the major cause of connector meltdown.
If there appears to be corrosion where the wire is crimped to the connector, you can use a small wattage soldering iron and resin core solder to solder it. Don't over cook it.
Squirt a blob of high temperature silicone grease in the connector before putting it back together and you should eliminate most problems.
Hitachi (OEM) Connectors
You can disassemble the connectors by depressing the brass "dog" that holds them in.
Cut any heavy corrosion with the sandpaper then finish up with the contact cleaner.
Spray with silicone spray and reassemble
New connectors are available from: