Topic: headlight issues

[Highwayhigh]

Alright, here is the rundown. Got my "bike-in-a-barn" 1978 CB550K about 2 or 3 weeks ago. I have done a fairly extensive go-over of the bike. Carbs rebuilt. Bike torn down to pretty much just motor and frame, and cleaned up. Opened up the majority of electrical connectors on the bike and cleaned out with electrical cleaner. The wiring harness in the headlight bucket makes me want to vomit. Whoever had this bike before was retarded and really cheated on a lot of maintenance. I'm talking wire splices where they twisted the exposed wire together and electrical taped over it. But I digress. Right now only the "high" setting works for the headlight. The Low beam works, but only at above 4k RPM and it's still a tad dim at that. So I have resorted to leaving it in High constantly. I understand a weak ground can cause this sort of thing, but why would the high beam work and not the low if it were a weak ground? I have gone through all of the exposed connectors and redone everything. Solid crimps, proper soldering. The works. But this problem still persists. I even ordered one of those "H4" headlights off of ebay, but to my dismay, it won't work. This is a conventional 7" headlight lamp, which is great. But on my bike the ring mounting brackets are attached to the headlight bulb itself. Is that factory? If so is there an alternative method for mounting a standard 7" bulb to the stock ring? I also don't have a connector for the H4 bulb but I suppose I could solder the leads on to it if I found a way to mount the ring to it. Anyways, any ideas for this? I appreciate the help. I have already inherited a wealth of knowledge from this website by means of studying and researching vigorously over the course of the past month. I would be utterly lost without this site. So thank you all again for your help!

-Logan

[Frostyboy]

Before being too concerned about upgrading to H4, I think you better sort out the issue of dim low beam.

Are you able to find a voltmeter & measure the voltage at the white wire with the bike idling & the headlight switched on?

I'm thinking maybe you're going to find an issue in the R/H control somehow, but that's only guessing. You're going to need a meter to be sure of a result.

I've got a H4 in mine, but it's not the original h/light. I've also fitted a dual relay for the H4 bulb. I didn't want to overload the poor old switch with the quartz bulb.
Good luck with the search.

[w1sa]

............... The Low beam works, but only at above 4k RPM and it's still a tad dim at that. So I have resorted to leaving it in High constantly. I understand a weak ground can cause this sort of thing, but why would the high beam work and not the low if it were a weak ground? ...........

Check the H/L switch contacts. You might find the contacts (especially the low beam) are crusty.

 A clean and polish might get it serviceable again and a thin smear of dialectric grease would keep it that way for some time.

[Highwayhigh]

Well I got the headlight issue resolved. The bulb just had a bad contact for the "low" filament. If you beat on it, it would come on and stay on. So it was a vibration thing. I also managed to get that other headlight mounted and it works fine. Low and high work flawless. I also shot voltage at the Low side to make sure it wasn't bad wiring, and it was solid the whole time.

Well now I have another problem that is making me want to bang my head against the wall. Got some fancy LED turn signals in the mail today. Front and rear. So I wire the rear ones up and they work great. Wiring the front up was not too bad, except these lights only have two wires, so I'm losing the running lights, no biggie. Well I wire everything up and go to check it out, and the tail light and gauge backlighting doesn't work. Well then I flip the blinker and the gauge and tail light start blinking. I double checked my wiring. I remember when I pulled off the old turn signals up front he had some sort of bizarre setup with a bunch of wires twisted and shoved into the splice points. Both turn signals were wired in to each other. But to the point: I am utterly lost. Looking at the diagrams, these are totally seperate systems. They don't even tie in together at all. How in God's name is this possible? Well, back to the bike, hopefully I can find something that works.

****EDIT**** Well I discovered the source of the problem. Somehow the stray brown tail light wire got stuck into the same splice as the stray blinker horn wire. Which for some reason isn't connected to anything. Now I discovered that I have a blown fuse for my tail light. Regardless, problem solved. That's 2 fuses in 3 days, wonder what's going on.