No headlights but weird indicator light pattern?

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

No headlights but weird indicator light pattern?

dyelawn
On my drive home the other day might headlights (both high and low) cut out a block or two from my house.  This is an '82 CB750C.  I've seen a bunch of posts here about how to troubleshoot this, but what seems unique about this was that concurrently with the headlight failure was a lighting up of the high beam indicator light.  As long as the key was turned, whether or not the bike was running or not, I got no headlights and the high beam indicator on the dash wouldn't turn off, regardless of whether the switch on the left handlebar was turned to high or low.

I opened the fuse box today and sure enough the headlight fuse is open.  Only, when I took the fuse from any other spaces, say, the neutral switch or the turn signals, and put that fuse (all others are still intact) in the headlight space, I still get no power to the headlight.  More bizarre, I put all the fuses back in their original spaces and now the pattern has changed.

As of now: busted fuse in the headlight space = no headlights, no unexpected dash indicator lights. Intact fuse in the headlight space = no headlights, high beam indicator light on.

Anyone know why this might be happening?  Thanks!
Reply | Threaded
Open this post in threaded view
|

Re: No headlights but weird indicator light pattern?

dyelawn
UPDATE:

I am still having issues.  I replaced the fuse and still no light - finally hit my limit of knowledge about electrical work and took it to someone local at a shop.  Of course, as I pulled up the headlight was working and there was nothing to be done.

Just today it cut out on me again.  Checked the fuse and it's intact.  So, it's not the bulb (because it started working again), and it doesn't seem to be a fuse issue.  Also, both times the headlight has cut out mid ride and not just after I turn it on, which makes me believe it's not a failure reconnecting power to the headlight within the starter mechanism as is often the case.  A valid assumption?

Bad wiring?  If anyone has ideas let me know!  I need this bike to get me to work everyday and the headlight is one of those bigger things I need to maintain legality on my commute!
Reply | Threaded
Open this post in threaded view
|

Re: No headlights but weird indicator light pattern?

slownugly007
Could be a bad connection to the bulb itself, bad switch or just a short somewhere in the wiring. These bikes have TONS of wires. The fuses on these bike too are junk in my opinion. The fuse holder itself may not be properly "clamping" the fuse. I tossed mine out and went to a more modern blade style fuse holder. Id check the the fuse box itself, wiggle the fuse back and forth and see if it cuts out, the do the same to the connector on the back of the headlight. If nothings wrong with either of those you may have to start following wires and make sure all connections are good.


Red/Black wire comes from the fuse box and goes to the starter switch, which from there jumps to a blue/white wire that runs to the headlight switch (this is your power to the switch). On the switch theres a white wire and a blue wire going to the headlight. White is low beam (comes on with the bike) and blue is high, the blue splices to run to the head light and the hi beam indicator. On the back of your headlight will be a connector with a white (on/low beam), blue (hi beam) and green wire (ground)

Hope this helps some?