Tail light is out but brake light works. Replaced bulb and fuse but no luck. Where should I look for a bad ground?

I hate these wiring harnesses. Why, oh why can't it be straightforward wiring?

Any help will be appreciated. Thanks.

 

try checking the circuit board built into the back of the light housing for corrosion...can cause all sorts of problems as all rear lighting goes through it.

 

I didn't notice any corrosion but will check again.

Any other ideas?

Thanks

 

wiring damage under rear fender is also common...and rear brake switch is mounted in a bad place for corrosion...is bulb holder getting power when brake is used ?

 

Yes, brake light works fine.

 

so just tail light...is that getting power at holder ?

 

seem to recall tail light running from acc fuse on mine...which one did you check ?

 

I checked acc fuse and other fuses as well. That stupid wiring harness makes it difficult to check the power to the light. It's on my plan to work on it again today.

 

Hoping it is the circuit board. It did look a little corroded but the voltmeter showed power coming through the tail light connection. Very, very odd. I'm out of ideas so I ordered a new circuit board. I'll try it next weekend.

 

The circuit board came in yesterday and I installed it last night. My tail light now works!
Thanks for your help Rasputin.

I still have one issue and that is the rear brake does not send enough power to light the brake light. Not too worried about that since the front brake is the main brake. I'll look into that another day. Today is for riding.