"Lights Out;" Possible fix for your Honda Nighthawk CB750 Headlight, if goes out

[Adventurer]

« [NHF] on: July 16, 2017, 12:06:00 PM »

My halogen headlight went out on me last night, on my way home, in the dark.

Took her apart, after church today, and noticed halogen plug is now blackened and bulb is smokey white, though filaments look okay (and fuse is still good, too).



Also noticed a random cut, red wire, within headlight assembly...



...some random, unconnected connections...



...whatever this is...



...but do have white, green, blue wire still all connected to what I'd always presumed to be, stock halogen connector...



Any insights to any of the above, welcome.

My gut is to replace white plastic halogen connector and bulb, which I'm hoping to do at local automotive parts store, since it's a Sunday, and my bike mechanic's closed.

Also, when looking at the headlight assembly in my '91-'92 CB750 Nighthawk Honda Service Manual (page 16-3), mine would appear to be missing the "(3) Dust Seal," at the rear.

Was hoping it would tell me the correct "(4) Headlight bulb" wattage and exact "(2) Headlight Bulb Socket," but it does not.

Nor would my Clymer Manual for Honda CB750 Nighthawk 1991-1993 & 1995-1999, appear to get into these specific part details, (on pages 284-287).

Surprisingly, the most detailed specs seem to be found on my Honda Owner's Manual 92 CB750 Nighthawk (page 86), stating:

"Headlight (HIGH/LOW) 12V-60/55W,"

Which I just confirmed is what I've got, (ruling out overloading wattage).



Any idea why the white, plastic "Headlight Bulb Socket" would blacken, that said? Normal with age or cause for concern? (Just don't want her and I to needlessly burst into flames someday).



Called local auto parts center, and they appear to carry bulb and socket for about $16. +tax. Only difference is all wires are apparently black on theirs, not color coded white, green and blue like these.

[Adventurer]

« Reply #3 on: July 16, 2017, 07:02:58 PM »
MYSTERY SOLVED!

Scoured the internet and found the culprit, thanks to a Nighthawk tech tip on the "Repair Tips" section of "Paul's Honda Nighthawk Pages," titled: "Dealing with Sudden Headlight Loss," contributed by John Vanveen, of Alberta, Canada, if you scroll down, on their site, in that category.

http://www.hondanighthawks.net/79cb650wdgr.pdf

The pic shown, is of my own NH. The solder he references, which is indeed loose/disconnected on mine too, is the one in the bottom right hand corner, which I will re-solder momentarily.