Getting to headlight wiring soon. Cleaned up wiring harness today and laid stuff out to get oriented. Complication is that my bike (early 62 cb77, wiring harness label says 61) had a four wire headlight switch (deceased) now will have a five-wire switch. Only difference seems to be an extra hot wire (black/white) to headlight switch. Some help is that my “new” dimmer switch from a CL (long story) also goes with five-wire switch. Further complication is that all wiring diagrams available to me (including one that came with original owner’s manual) show the five-wire switch and parking light in headlight that I don’t have. So a bit confusing.
Honda’s use of green for hot to headlight switch and then green for headlight ground doesn’t help. I think I’ve got it figured out, but could use some reassurance.
The way I’ve got it laid out in breadboard seems wrong, looks like the instrument lights would stay on all the time. I think I need to hook the green hot wire from back of bike to the brown wire going to switch, then connect instrument lights to brown between headlight switch and dimmer switch.
Re second pic I’d assumed that old headlight switch fried because of lack of tiny h-shaped insulator in the dimmer switch (part of long story re dimmer switch) which grounded hot wire from headlight switch. But burnt contacts are ones that go to rectifier. Does this make sense, or is there a problem with the rectifier? After much study just how rectifier fits into big picture is still eluding me. Everything I've seen on testing rectifier involves having bike running, is there another way? I don't want this thing to sizzle first time I turn on the key.
I know some of you guys are into solving this kind of puzzle, so if some expert could take a few minutes to look over breadboard pic and your wiring diagram and advise, it would be much appreciated. I tried to label stuff to make it easier. I don't know if having a diagram of four-wire system would help at this point, given the hermaphroditicism (is this a word?) involved.
As for grounding, see previous post, after study and advice here (thanks!) I see that headlight bucket indeed needs to be grounded to frame, iffy given new paint, rubber washers between headlight ear pieces and everything else, and greasy ball bearings in steering stem. So just to be sure I’ll run a ground from where headlamp grounds to bucket to bracket for coils which will be grounded to both frame and engine. A green wire, I suppose.
I’m getting there on restoration and plan to fill in some details later. Right now I’m just trying to get this motorbike built so I can ride, ride, ride. Having a great time. Thanks for your support. -- Lee
Headlight bucket wiring
Headlight bucket wiring
OK, if the pink & yellow are burnt 'all the way along' their respective lengths, then I'd suspect a short circuit (to ground or via excessive load); this is unlikely, on the proviso that your harness has the prescribed 15A fuse installed. Said fuse will protect the rectifier and all its associated cables, as this is all rated at or above a 15-Amp capacity. You can test a rectifier with a suitable multi-meter; see my post here http://www.honda305.com/forums/viewtopi ... highlight=
However, it looks to me like the wires have overheated at their solder joints (I'd lay money that there's no sign of meltdown on the yellow & pink in the harness, or you'd have mentioned that!); the solder has become so hot on the yellow that it has melted and 'let go'. Now, the likelyhood here is that there has been a build-up of corrosion (possibly caused by water ingress) or dirt / dust / crud within the switch; this would have created a resistance at the point of contact(s), which, in turn, would have created the heat. I'll come back a little later with the solution for switch substitution later today ~ I need to get out of the pit and walk my pooches! But, on a final note, beware the wiring diagram; there's a glaring error on the lighting circuit.
basically have it figured outThanks for reply Steve, and for your personal attention earlier via email. I was hoping for your input on this. Thanks too to Mike Mullins who took and sent me some helpful pix of wiring on his current project when I asked. Great folks on this forum!
After an afternoon of ohming (with multitester, not chanting, though that might have helped) I've come to the conclusion that conversion could be done but it's not worth it. I just need to do what I should have done in the first place and trade the five-wire switch for a correct four-wire. Ed offered to do this when we realized I'd brought wrong switch back from Kerrville, and again last week. Stubborn me said "let me play with it, I think I can make it work." Four-wire will plug right in to existing harness, just need to hook brown wire to new dimmer switch to into green cluster. Conversion to five-wire would involve butchering my original wiring up inside bucket, which I'd rather not. LM was right again, as always, but like any good guru he let me find my own way to problem's solution. So puzzle out conversion for your own intellectual satisfaction if you want to, Steve, but don't do it on my account. Re error in wiring diagram, I had a feeling there was something funky about it but couldn't quite get my head around it. Please elucidate? Does anybody have a wiring diagram for four-wire version? I don't really need it but wouldn't mind having it in my archives. Still a little concerned about burnt out rectifier terminals on switch. Fuse wasn't blown, wires were in good shape except right where they connected to burnt terminals. Missing insulator in dimmer switch would have let power wire go to ground when headlight switch was turned on. "Missing" status of insulator depends on assumption that I didn't lose it when I disassembled the switch, pretty sure I didn't but it's possible. I'll check out thread on testing rectifier. Thanks again for your help, guys! -- Lee
rectifierI copied rectifier test procedure to my archive, printed it out, tested with ohmeter on rx1. Had continuity where it should, none where it shouldn't so I guess it's good. Showed a bit of resistance but I assume that's to be expected. So apparently I'm good to go. Thanks again you guys. --Lee
Correct. A diode is a semiconductor and, thus, will present a degree of resistance, which is one of the reasons why it gets hot. A silicon diode will offer a resistive absorption of 0.7V in just doing its job as a 'non-return valve'; older selenium diodes sometimes as much as 1.5V. Here's a really informative, if deep (in places), tutorial on diodes http://en.wikipedia.org/wiki/Rectifier The dimmer switch was deffo-not-ly to blame here; the problem was solely at one, or both, of those contacts for the AC circuit boost, i.e. yellow or pink. My logical, if annoyingly stubborn, diagnosis tells me that, had the dimmer switch been at fault then the meltdown would have emanated from there, along the brown wire back to the HL switch, then along the path back to the ignition switch and, subsequently, blown the fuse. As it was, the overheat would have been within the HL switch, remaining local there; localised meltdown / burnout is always due to a point of resistance. I don't understand howcome yours, as a '62, has a highbeam indicator; that wasn't, I believe, introduced until '64, within the Type Id instrument cluster. I'm working on a colourcoded wiring diagram, which I'll post when it's finished. I've no knowledge of the 4-wire switch; how many switch positions does it have? I can only surmise that the 'parking lights only' position didn't exist on this type.
thanks steveThanks for info, I'm going to switch (no pun) from theoretical to pragmatic approach here, install it with new old four-wire switch, which Ed is sending, finish up and get bike running, and see what happens when I turn on light switch.
Re your questions. Speedo was replaced in late '65 when a friend ran bike into back of a parked car. He paid for/arranged the repair so my memory is foggy but I remember a big crease or dent in front of speedo rim. Suprisingly, they made do with old headlight bucket, which I'd replaced in early '64 when another friend ran into another parked car, ruined the bucket but spared the speedo. Old speedo had a hook on bottom for a spring that went to bottom of bucket, new one just mounted with two screws into top. Never quite fit right, wouldn't fit anywhere near right with newer gasket, old one was shot, so I'm now on my third headlight bucket. I'm gonna be more careful about who I let ride my "new" bike. So I guess that's where the high beam indicator light showed up, my owner's manual doesn't mention one, can't see one in pix there of speedo. It doesn't show on either version of wiring diagram I've got either. So I guess it didn't have one originally, that's a detail I just don't remember. My four-wire switch has only two positions, on and off. Turning ignition switch to far right leaves tailight on with key removed, that's the only parking light. So what about that glaring error in wiring diagram, I'm curious. Thanks for your help! Lee
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