Topic: Patina Hyena - 550/650 674cc Hybrid Cafe Build

[DaveBarbier]

Question: Is there a better alternative to these Emgo key switches? If you watch the video you can see just the speedo illumination (not sure why just the speedo) flickers if I wiggle the key while in the "on" position. Do these things need to be grounded with their body? I just have three wires coming out of it. I smack the headlight and reach in to wiggle the wires just to make sure it's not other wiring. It seems to be only the key switch.

Any help would be appreciated. Thanks.

Also, when riding home tonight I went to switch on my high beams and the entire bike went dark. Engine shut off and wouldn't turn back on. All lights went off except for the speedo illumination. Weird, yes. Thought I blew a fuse but waited a second and turned everything back on and I was good to go. I did notice that my headlight can shut off if I play with the high/low switch. Any takers on this one?


---
1978 Honda CB550K

[Restoration Fan]

I think there's a short somewhere in that switch body.  To interrupt current like that cannot be an intended outcome of bumping the key.

[SOHC4 Cafe Racer Fan]

I agree with Ron.  I think you have loose wire in the key switch.

[DaveBarbier]

Thanks everyone. I will go out and get some info for you with my multimeter. But just a little info. Yes, it's a three wire universal Emgo switch. I got rid of the stock one because it was too big. I wired it up with a relay to help lessen the load and hopefully save this little thing from burning up. I posted a question a while back on how to wire it up and this was Hondaman's reply which is how it's currently wired.

"Connect the Red/White wire through a fuse to the #30 post on the relay. This is the "source" power. Connect the bike's Black (Ignition) wire from the harness (cut it away from the keyswitch) to the #87 terminal on the relay (this is "switched power", then). Connect the Black that you cut from the key to the #85 terminal, and connect the #86 terminal to Green (ground). These last 2 are the coil of the relay: when you now turn on the Key, it connects the Red/White (through the fuse) to the Black. The Brn/Brn-Wht wires stay on the keyswitch, and control the Park light and taillight stuff."

Link to thread if you care. It also has the wiring diagram of the switch I'm using.
http://forums.sohc4.net/index.php/topic,134413.0/all.html

On the actual switch I BELIEVE what's connected is a red to one post, a black to another and finally the brown and brown/white together on the last post. I can double check that when I'm out there.

Because I have a relay on the switch, will I have lower numbers when I measure with the multimeter?
(Electronics aren't my forte even though I wired this up and completely redid the wiring under the seat successfully. The knowledge seems to enter my head only for the amount of time needed to complete the task. Then it gets replaced with beer and the next project.)


---
1978 Honda CB550K

[DaveBarbier]

Continuity/resistance from high/low switch housing to engine bolt: there is continuity and it's .6 ohms resistance. Is that ok? My clipons are painted black but it might have a path going through the clutch cable. I'll sand some paint off and retest. Does the high/low switch housing ground itself through the body or is there a grounding plate or pin?

Key switch:
OFF
13.3 volts to red only.

ON
13.3 volts to red
12.7 volts to black
12.7 volts to brown, brown/white

Key ACC:
13.3 volts to red
12.7 volts to brown, brown/white

Can I measure resistance while it's connected to power? My meter clicks when I do that. I think it's bad and I'm tripping a little internal breaker. Right? The key switch must be removed from power, no? With ground from battery disconnected, resistance values are as follows:

Key OFF:
Open Loop on all contacts.

Key ON: (while wiggling key)
Ranges from .4/OL from battery to ignition and ACC

Key ACC: (while wiggling key)
Ranges from .4/OL from battery to ACC

Seems to me the key switch is bad. And I can see the power contact on the back wiggles even after it's tightened down. New key switch, no? I see on eBay an OEM 4 wire CB550 small key switch. These have to be better quality than this EMGO, right? Any other small key switches that you guys recommend?



---
1978 Honda CB550K

[DaveBarbier]

Anyone with thoughts on my numbers? Specifically the resistance value of the high/low switch housing to engine bolt? I bought the OEM 1975 CB550 (four wire) key switch. Plan on just wiring it up to my three wires.


---
1978 Honda CB550K

[Maurice]

If you have a ground somewhere, you need to measure continuity, not resistance. Besides, it looks like an intermittent ground, which means you can measure all day and not find anything until you wiggle the right spot...

It's a PITA for sure, inspect connectors inside of harness, etc. There's probably some wire insulation cracked somewhere that could be causing this. Could be key switch itself? Does it do it when you hotwire the thing?

[DaveBarbier]

Oh, well I'm 99.99% sure the switch is crap. I wiggle the key in the switch while the switch is disconnected from the bike and the continuity tone on my meter is intermittent while testing the contacts. To me that means the switch goes in the bin.

There is also continuity from the high/low switch housing to an engine bolt. That tells me the housing is grounded but the resistance of that ground is .6 ohms. Is that ok? Does resistance not matter in a ground as long as it has continuity? Regarding the high/low shutting off the headlight temporarily or while I wiggle the little switch lever, I know and saw that the contacts are a little worn. I tightened it down and cleaned them but have yet to test it to see if it's better. I might replace that so that's not a concern right now.


---
1978 Honda CB550K

[Maurice]

I don't think it matters that the housing itself is grounded, as long as wires and stuff that is powered inside is insulated from it. Which it may not be... Now the HI-LO switch can probably have a position in-between where there won't be any light connected at all, the way it's made it looks like you could wiggle the switch itself and interrupt the flow.

If in doubt take the switch out of the equation by wiring low straight at the plug with a jumper (and electrical tape in case) and test things out. To find a short you'll have to eliminate stuff one after the other.

[DaveBarbier]

I don't think it matters that the housing itself is grounded, as long as wires and stuff that is powered inside is insulated from it.

Hm, ok, makes sense. Yeah all my wires inside are in good condition. I looked them over when I took it all apart to route the wires through the bars.

...the way it's made it looks like you could wiggle the switch itself and interrupt the flow.

That's exactly what I think is going on. The switch moves vertically for the high/low but when I press it horizontally to the right it shuts it off. I can see it moving away from the contacts when I look inside. Glad you said that!
I originally thought my two issues were related but I think now that it's just a coincidence. Faulty key switch mixed with high/low switch a little worn. Will replace the key switch this weekend and report back. Thanks!


---
1978 Honda CB550K

[DaveBarbier]

I'm not sure I agree with your belief that continuity is a better indication of circuit health. It takes virtually nothing to get continuity. Resistance on the other hand is a measurement of the quality of the signal and will indicate shorts, corrosion, poor connections, etc.

The Key switch does need to be grounded itself via the mounting hardware. The handlebar switches are also grounded via their mounting to allow power (from Black, BR/WHT, etc) to be transferee and delivered to a component.

Dave, I think your earlier measurements indicate a poor quality switch.

Yes, I agree that the switch is poor quality. On order is a Honda switch from an earlier bike because it's small like the crap one I have so I can put it in the same place. It's used, but off a low mileage bike, the seller says.

Resistance seems like a better test but I don't know what's acceptable. Is .6 ohms too much resistance? Should it be closer to .2 or something? Or do I have a good ground already?

Thanks for the input.


---
1978 Honda CB550K

[Maurice]

I'm not sure I agree with your belief that continuity is a better indication of circuit health. It takes virtually nothing to get continuity. Resistance on the other hand is a measurement of the quality of the signal and will indicate shorts, corrosion, poor connections, etc.

The Key switch does need to be grounded itself via the mounting hardware. The handlebar switches are also grounded via their mounting to allow power (from Black, BR/WHT, etc) to be transferee and delivered to a component.

Dave, I think your earlier measurements indicate a poor quality switch.

Cal, I mean that when chasing a short you will have a hard time on resistance alone. Most times shorts are intermittent and only show up when a wire touches something else. Resistance will be infinite when you happen to be measuring, most times. Besides there's no specs on what resistance usually is between most points, except when you're testing inductors.

Most times I find them (luckily not have to do often) by visual inspection and process of elimination...

Hope Dave finds his quick.

[DaveBarbier]

I actually don't think I do have a short at all. I'm pretty sure it was the key switch and the loose high/low switch. I will still sand off some paint on the clipons but I think the controls on the bars are/were functioning normally (other than the aforementioned high/low switch).

I did describe my bike going dark when I turned on the high beam but I'm thinking that was a coincidence. It was also a bumpy road which could have vibrated the key switch shutting down the bike temporarily. I didn't blow a fuse and turning the key off and back on fixed the problem. While continuing to ride I was able to play with the high/low and it didn't shut down the bike...but it did turn the headlight off temporarily.

Thanks guys


---
1978 Honda CB550K

[DaveBarbier]

Ok, so got the '76 550 key switch. There are three positions: off, on ignition (red dot), park (black dot). Please correct me if I'm wrong.

When the key is turned to "on ignition" there should be continuity from red>black, from red>brown and from red>brown/white, correct?

I just measured and I only get continuity from red>black and then from brown>brown/white. Doesn't seem right to me. I'm asking because when I hooked it up everything works but my tail light, though the brake light works. Now if I "jump" red>brown/white or red>brown on the back of the switch the tail light turns on. Is this key switch not compatible with my '78? Is this switch bad?


---
1978 Honda CB550K

[Maurice]

Switch is normal. Red to black and brown to brown/white respectively. Black feeds back to brown/white (then brown) through light switch. Park just switches red to brown (tail only). When you switch to on you should have 12v at brown/white, check that.

[DaveBarbier]

Switch is normal. Red to black and brown to brown/white respectively. Black feeds back to brown/white (then brown) through light switch. Park just switches red to brown (tail only). When you switch to on you should have 12v at brown/white, check that.

Ok, I'll check that tomorrow morning. What do you mean by light switch? The high/low?


---
1978 Honda CB550K

[Maurice]

Switch is normal. Red to black and brown to brown/white respectively. Black feeds back to brown/white (then brown) through light switch. Park just switches red to brown (tail only). When you switch to on you should have 12v at brown/white, check that.

Ok, I'll check that tomorrow morning. What do you mean by light switch? The high/low?


---
1978 Honda CB550K

Yes Hi/Lo. That is where black goes to brown/white. According to the wiring diagram brown/white also goes to the instrument lights, your hi/lo switch might require some cleaning.

[Maurice]

Actually, I took another look at the wiring diagram, on your 78 there should be a black going to headlight bucket and connecting to brown/white directly, NOT through the hi/lo switch. If that's missing or corroded or barely hanging the bike will work ok except for taillight, instrument lights and markers (turn signals always on which I suspect you didn't connect). Anyway, trace the black to brown/white for the source of your woes.

Tail light fuse should be good since it works when you jump re to brown.

HTH

[DaveBarbier]

Ok, I'll check that out. But I don't see what you're describing in my diagram. I do see black>brown/blue via that yellow tube black tube jumper...which leads to the fuse block and then goes to brown/white. Either way, I do see that if that's not connected or corroded then the brown and brown/white would be getting no power.

Actually, thinking about it and looking over the diagram I'm thinking my tail light fuse IS blown. I may have misled when I said everything turned on...everything except the backlight for the speedo (I stupidly and confusingly hooked up the gauge backlights differently. Speedo to brown/white and tach to black. I'm going to change that.) This way the tail light could still light up when jumped via red by going direct to the brown wire. Does that sound right?


Thanks!


---
1978 Honda CB550K

[Maurice]

Yes sounds right. That yellow/black tube is what connects tail light and instruments. It's the same as the '78 750 seems like.

That's why I said "trace" because your wiring may be modified, your bike sure is. And the way the wiring is on the diagram yes you could simply have the taillight fuse out. Hope it's that simple.

Ride on.

[DaveBarbier]

Yes sounds right. That yellow/black tube is what connects tail light and instruments. It's the same as the '78 750 seems like.

That's why I said "trace" because your wiring may be modified, your bike sure is. And the way the wiring is on the diagram yes you could simply have the taillight fuse out. Hope it's that simple.

Ride on.

Got ya. But, if it did blow, trying to figure out why will be another story.
Thanks Maurice


---
1978 Honda CB550K

[Maurice]

If they're the old glass fuses, sometimes they blow just looking at them. Utter crap. Replace with modern blade ones with holder from HondaMan.

[DaveBarbier]

If they're the old glass fuses, sometimes they blow just looking at them. Utter crap. Replace with modern blade ones with holder from HondaMan.

I tossed those things away when I got the bike, haha. I have a blade holder that I got off eBay.


---
1978 Honda CB550K

[DaveBarbier]

Blown tail light fuse. Not sure why it blew in the first place, though.

Thanks for all the help!


---
1978 Honda CB550K

[SOHC4 Cafe Racer Fan]

Dumb Question: Any unshielded wiring coming/going to the taillight (near grommets, etc.)?