Tail light wiring

[Sgriger534]

Does anybody have a picture of the tailight wiring, i use to have a trunk and the wiring was a mess, and i tried to clean it up and now my bike won't start. I have looked at the wiring diagram but i think i am missing a wire

[fredintoon]

Does anybody have a picture of the tailight wiring, i use to have a trunk and the wiring was a mess, and i tried to clean it up and now my bike won't start. I have looked at the wiring diagram but i think i am missing a wire

Hi sgriger,
stock wiring has these colours:- Tail lights & number plate lights are blue (L) brake lights are green/yellow (G/Y) left signal is dark green (D/g) right signal is brown (Br)
Each lamp must have it's own black (B) wire connected to the black wire that goes to the frame.
The rear end wiring should plug into several connectors under the seat. What's there on your bike depends on how medieval to PO got on the wiring
FWIW, I see no way that disconnected tail light wires can prevent the bike from starting.
Look for another cause.

[Sgriger534]

it looks like the tailights shar a ground with the ignition unit.

[psycoreefer]

The important grounds, one is from battery "-" to the frame, make sure its clean and tight. Second is from frame to engine, again make sure its clean and tight. Third is held down by the reg/rectifier screws, clean it up and put it back. I've read about another ground up near the headlight but my bike doesn't have one there.

I agree that messed up taillights shouldn't stop the bike from running.

Have you checked your fuses? The glass ones can look good but not work. Try "wiggling" the wires on the TCI? Trying to think whats in that area you might have bumped by accident while working on the lights that would cause a no-start.

Can you clarify not start? does it crank but not fire? Do the lights come on?

You can get a full factory manual from the link in "Catatonic Bugs" signiture, it has a wiring diagram.

[Sgriger534]

It cranks and the lights come on, but i get nothing out of the spark plugs

[psycoreefer]

No spark... OK
First thing I'd check (and you can read that as replace)is the ignition fuse. After that I'd start at the coils and work backwards, do you have +12v at the coils? You'll need a multi-meter.

[Sgriger534]

what is the ignition box suppose to have for voltage at the termanials. On the bigger plug i have atleast ten and a half volts on every wire except the ground the a red with a yellow tracer. and the smaller plug has .5 volts on each wire

[psycoreefer]

Is that with it "unplugged" from the TCI, or are you plugged in and back probing the connections?

[Sgriger534]

Doing a little back probing

[psycoreefer]

I can't say I've ever backprobed the TCI with the ignition on, hopefully someone else will jump in to confirm...

Maybe I'm reading your post wrong but Red/yellow isn't the ground, it should show battery voltage only when cranking.

Not sure about what should read on the others.


My first gut instinct is that 10.5v is a pretty low, are you sure your battery if fully charged. I'm not sure about our 11's but I know honda's TCI's need at least 10v to work, and if your starting with 10.5 then I'll bet its dropping well below 10v when your cranking. Try hooking up a charger or booster pack and seeing if it fires up.

[Sgriger534]

your right, i posted that wrong, it has voltage when cranking, i am going to check the connection where the red wire splits and runs to the coil, and handlebar switch, i used ignition sealer because there was nothing protecting them and i wonder if i didn't mess the connection up