Just rehabilitated the entire harness of a CB750. Took about two weeks working through the weekends and almost every evening. Manually cleaned EVERY connector:
Some of the worst connectors looked like this:
Vintage connections makes a tool that helps getting connectors apart:
Keep a notepad handy for those multi connector blocks:
YUCK!
A Dremel with a wire wheel is a POWERFUL tool!
Steel wool does a good job of cleaning rattlecan overspray off the wire insulation that some goob PO got all over EVERYTHING:
Nice!
Don't forget to bend the retaining tabs back into place:
Viola'!
I then gave all the newly cleaned contacts a shot of tuner cleaner/lubricant:
http://www.radioshack.com/search/index.jsp?kwCatId=&kw=tuner%20cleaner&origkw=tuner+cleaner&sr=1Purple Power (or "That Purple Stuff") does a bang up job of removing paint from plastic without damaging the plastic. Use gloves when removing parts from solution and wash parts thoroughly. It does not appear to harm plastic, but it's a little rough on the skin.
The female connectors (both bullet and spade) are more difficult to clean (insert favorite chauvanist remark here) but the same principles apply. For the female spades I used the dremel w/wire wheel for the outer part of the connector (just to remove any oxidation that might promote more oxidation) and then used a narrow strip of tin with a narrow strip of 320grit sandpaper folded over it to clean the inside of the spade connection. A pinch with the pliers prior to reassembly to assure a good, tight connection finishes the spade connectors (don't forget the locking tab on these too). The male bullets clean up the same as the male spades, while the female bullets require either a small diameter wire bottle brush (.177 cal bore brush is a popular choice) or an assortment of small diameter diamond stones for the Dremel (my choice). Again, a little pinch with the pliers to assure a tight connection, a little shot of tuner cleaner/lubricant, and, if you did everything right, you're good for another 30 years.
While I was at it I pulled apart the switches and cleaned them too. Here is the rear brake switch at the rear brake foot pedal:
Before:
After:
If you don't want to tackle the whole harness at once (quite daunting) then start with the primary circuits starting at the fuse box. Clean all the fuse holder connectors and harness connections to the fuse box. Then clean all the problem connectors in the headlight bucket (the headlight circuit in your case). You might want to inspect/clean the charging system connections too for more reliable performance. I did this more targeted approach (as opposed to the whole harness) with my daily driver a couple years ago after it started blowing the main fuse. Still trouble free after this form of maintenance. This process WILL try your patience.
Oh yeah, DISCONNECT THE BATTERY!
