Topic: 77 cb400f headlight not working

[BobW]

Not much of a bike machanic - learning as I go since I got my 77 cb400f a few months ago.  My headlight would sometimes work sometimes not.  Replaced the lamp, checked/replaced the fuse.  Same thing for a while.  Now it just doesn't work at all.  Previous owner put a on/off toggle for the headlight in the end of the left handlebar grip.  Going to check those connections next - does the grip just slide off (not easily I'm sure) or is there more to it than that?  What else would I look for and where?  Many thanks in advance.

[b52bombardier1]

I just had to replace the entire right side handlebar switch assembly on my CB500 to solve a similar hi / low beam switch problem.

I had to undo the throttle cables at the carbs to get enough slack to remove that entire assembly and then fish the new one back down the inside of the handlebars.  That was the hardest part of the job . . . pushing and pulling those new wires.

Rick

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[Bodi]

A switch sticking out the end of the bar?

Anyway... heating the grip should get it to slide off, it's either just a tight fit or some adhesive was used (hairspray was popular once, does that stuff still exist?). I pour boiling water on them but I don't generally see electrical stuff that would be exposed to it.

[przjohn]

If the grip does not come off easily, cut both grip offs with a razor knife and put new grips on. Grips are a one shot item if they have been glued on properly with grip cement. Save yourself some headaches for the price of a set of grips and cut 'em off.

 But back to the toggle on the end. You have to love it when Electrical Gremlins send folks down to Radio Shack for a Toggle Switch. "Well hell, I can't figure this damn thing out, I'll just hot wire it". They are usually found in the headlight shell or maybe a side cover. A grip end is a first for me. I am going to guess a PO lost his headlight and ran it directly off the battery through the  "Bar End Toggle" method.

[BobW]

Thanks for the replies.  Good news and bad news on this little project.  I sprayed some contact cleaner in the switch (saw the idea in a similar post from a few years ago but might have been a dumb thing to do).  Good news is the headlight now works (so I guess that helps determine where the headlight problem might be???).  Bad news is the starter button now sticks in and I have to pry it out to stop the starter.  Not the easiest thing to do.  Looks like a new starter switch is in the future.  The wires go through the handlebars - right?  Sounds like an expensive trip to the shop.  Major bummer.

[b52bombardier1]

Not a difficult or expensive job. The switch cluster should still be available. And it's a push pull technique to get those wires down the handlebars.

Use the wiring diagram to reconnect things. None of this is difficult. Just don't pull the wires too hard getting them down the handlebar tube - could break the wires or insulation.

Rick 

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[BobW]

Thanks Rick.  Would I need to remove the handlebars?

[b52bombardier1]

It helps to remove the bars but I did mine last week with it still attached  by the bike's other cables.

The big thing is getting access to the hole on the bottom where these wires spill out. That's an absolute must.

Rick

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[BobW]

Great info.  Thanks.  Do all the wires end up in the headlight bucket for attachment or will the gas tank need to be removed to route wires where ever?  Just trying to get a handle on what might need to end up where to determine my comfort level.  Many thanks

[b52bombardier1]

No need to remove the gas tank. And yes, all of those wires connect up somewhere in the headlight bucket.

Rick

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[BobW]

Thank you.  I think I'll give it a go.

[przjohn]

Lube is your friend with those wires. I use original Spirits Polish to help them slide through.

[Pat_at_APE]

I just had this same issue on by 77 CB750SS.  Had to replace the right switch assembly to resolve it.  The problem was the starter button headlight interrupt. 

Got mine through 4into1.com in just a couple of days. Great service.

Regards,
Pat at APE