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1985 CB 450SC Nighthawk no power to headlight

2K views 3 replies 4 participants last post by  Emil 
#1 · (Edited)
Noob here, just got this CB 450 cleaned the carbs, brakes, tires, new blinkers, blah blah. Thought it was all good to go. Rode it one day everything was fine i know the headlight WAS working (I made sure) i change oil about to go for a ride then realize headlight isn’t working test headlight by hooking it up to battery and its good. Then i start looking at the wiring I take off the turn signal switch/horn/clutch handle and next thing i know the whole bike is dead no dash lights no nothing.
I end up taking taking apart the ignition switch not the problem but needed to be cleaned anyway.

Okay so today i got some new fuses solved the dead bike problem and soldered a wire to the bottom fuse holder since one of the clips was broken wrapped said wire around fuse. Everything seems to be solid now except I still have no power to the headlight. I have voltage in and out of the middle headlight fuse while bike is in ON position and no voltage either side when OFF.

I was reading a bit and think ill take apart the starter switch now, but if anyone has any ideas any help is appreciated!
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Update it was the starter switch
 
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#3 ·
Hello, some Honda models run power to headlight thru the start button on right handlebar switch, When starter button is pushed the switch opens the circuit to headlight to allow full battery voltage to starter and ignition components. Only the headlight shuts off, the starter relay circuit is energized with full battery voltage. When start button is released the headlight circuit is re-energized. Those 2 functions take place inside start button switch. Sometimes the internals of the switch can get damaged or "gumed-up" , Check for volts in and out of the sub-switch, that includes start button inside right handlebar switch. If contact is open or intermittent try to flush switch with WD-40, be careful what type of cleaner/solvent is used, the plastic is fragile.
The headlight sub switch could be bypassed inside headlight and headlight would remain "on" and not shut off in engine crank mode, a simple toggle switch could be installed to "jumper" wire to allow shut off of headlight for engine start with a low battery . Good Luch. HJ
 
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