Topic: 78 cb550, tail/brake light issue - SOLVED

[bookah]

My tail/brake light stopped working suddenly. I thought it was a fuse issue, nope. Thought it might be the bulb, nope. I'm at a loss for what it could be. I will be checking the wires with a multimeter later today when I get home, but is there anything else I should be looking for?  The connections seem clean, all other lights including the rear turn signals work fine.

Both the normal running tail light and brake light simply do not turn on, squeezing front/rear brake do nothing. The brake light has three-wires - brown, green/yellow stripe and green solid. The green solid was not plugged in to any connector when I took the seat off to give it a look last night. That said, I looked for where it could be plugged in, and there simply isn't a place for it.

Should I take off the headlight and see if there is a loose connection there? 

I have been using this diagram as a general guide: http://oldmanhonda.com/MC/wiring500.html

EDIT/SOLVED: I went to the source. The ground wire had become disconnected within the brake light housing. Boom. Do I feel stupid? Slightly, BUT IT WORKS AND I JUST GOT DONE RIDING YES!

[Tetter]

Brown is your rearlight. yellow/ green your brakelight, andsolid green should be connected to ground.
Indeed when the green one is not plugged in you will have neither.

Check again, there should be a connector, probbably a multiple as also ground for the rear turn signals are on there.

[bookah]

Brown is your rearlight. yellow/ green your brakelight, andsolid green should be connected to ground.
Indeed when the green one is not plugged in you will have neither.

Check again, there should be a connector, probbably a multiple as also ground for the rear turn signals are on there.

So there is a multiple connector, but there is no logical place to plug in that wire. I tried plugging it into the multiple as the diagram shows, but I still couldn't get it working.

[DH]

look for a spade-like male connector that is hidden underneath the tail light housing (bracket side). it is the grounding point for the green wire.  The older models are like this and I suspect yours is as well. Worth checking..
Assuming the green wire is connected at the other end under the seat as well

[bookah]

I tried plugging the green wire into the connector that houses the ground wires from both rear turn signals and nothing. I'm at a loss at this point. Tomorrow I'll get my buddies multimeter to see if its even getting power.

[Tetter]

Any luck solving your problem ?


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[bookah]

Any luck solving your problem ?


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Nope. Things I have tried:

• Plugging in the ground from taillight into the multi-connector
• Changing bulbs (although I have the exact match on order, I matched as close as possible and still nada)
• Changed fuses

Things I need to do:

• Check wires with multimeter
• find electrical guru in los angeles willing to help me

I decided to order a special exact match replacement bulb on amazon that I couldn't find for the life of me locally just to rule that out. I have attached pics of the connectors in the meantime. When I bought the bike the light was working perfectly, and all other lights on the bike still work great. When I first opened it up it looked similar to the pics in the album linked below. You can see the green ground wire is unplugged.

http://imgur.com/a/nYdZw

[Tetter]

Looks like the pins fir the turnsignals are a bit "deep" in the multiconnector. You should be able to put the loose green wire in at the back, where the cable from the connector is. Won't the lights work of you hold the cable againat the connector ? That should provide the ground..... Otherwise indeed, check if you have power on brown or green/ yellow when bracking


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[bookah]

Looks like the pins fir the turnsignals are a bit "deep" in the multiconnector. You should be able to put the loose green wire in at the back, where the cable from the connector is. Won't the lights work of you hold the cable againat the connector ? That should provide the ground..... Otherwise indeed, check if you have power on brown or green/ yellow when bracking


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I tried and got nothing. At this point I am waiting for the exact match bulb to arrive just in case the issue is that simple as well as borrowing my buddies multimeter to see if the wires are even getting power.

Thanks for all the advice. I'm hoping to get this cleared up before the weekend!

[DH]

just to add, since both signals work when plugged into the green,( ground) 4 way, i'd suspect that circuit  is ok.
 make sure the tail/brake light circuits are delivering current, and that the light bulb contacts are not smashed flat,
burned or corroded, and that the ground wire attachment to the socket is not broken off, if there is one. bulb socket integrity will have negative effects on operation too. corrosion/rust/looseness of fit, bent/damaged.
Hard to tell what your situation, maybe non factory light?  just my .02

[bookah]

just to add, since both signals work when plugged into the green,( ground) 4 way, i'd suspect that circuit  is ok.
 make sure the tail/brake light circuits are delivering current, and that the light bulb contacts are not smashed flat,
burned or corroded, and that the ground wire attachment to the socket is not broken off, if there is one. bulb socket integrity will have negative effects on operation too. corrosion/rust/looseness of fit, bent/damaged.
Hard to tell what your situation, maybe non factory light?  just my .02

Will do, thanks for this. Indeed not factory. At this point I can hardly wait for the replacement bulb to come in to test all of this out. At this point my feeling is the issue lies somewhere within the bulb socket or perhaps even the ground wire itself.

[bookah]

Just for peace of mind, there is nothing in the headlight bucket that could cause this right?

[bookah]

Looking at the photo you posted, I am wicked confused. From the lights, there appears to be a BLK, and and BLK/WHT wire.y have the BLK/WHT connected to solid GREEN. The GREEN appears to be stock Honda ground. Are you certain the lighting elements you have use BLK/WHT as ground? It would normally be reversed, BLK as ground and BLK/WHT as voltage. If so, BLK/WHT needs to connect to BRWN.

Those are the aftermarket turn indicator wires, currently working perfectly.

Can you take a few other pictures, a bit more clear, showing all the connections? The wires from the tail light, the wires from the indicators, and those available from the stock harness above the fender would be helpful.

I'm currently at work but I edited tags on one of my previous images:

http://imgur.com/jdQN4mE

Do you have a multimeter? If so, check for continuity between BLK from the light to the battery NEG terminal. If you don't get a tone, check BLK/WHT. And check your solid GREEN. Do this before the pictures, and let us know. Please?

My cousin has a multimeter. I've been stalling going over to grab it since I'm waiting on a few parts to arrive.