I was testing my new Custom Dynamics rear fender tip light before installation and plugged it in with the acc switch on. There was a small arc and now neither my fender tip light or BrassAss taillight will light when the acc switch is turned on. Both still light up when the brake is on. It's just that neither will work as a running light. My BrightAss tail light worked fine as a running light before my screw-up. Since the plug is a 3 prong plug, I'm guessing one side of it has no power.

I assumed I had popped a fuse, but checked all the left side 15A fuses with an ohm meter and all check good. All other electrical works fine on the bike.

Any suggestions or ideas about what else might be wrong?

Thanks

 

to see if your lights are getting power; a meter ( or often a trouble light works better as it is a 'real' 12 volt load) to the plug

black is ground
blue is run
red/yel is brake.

so see if you are getting power thru to fender to the rear.

mike

 

On the fender tip light plug, I'm reading no voltage with just acc on. When I press the brake, I'm reading about 11.8v from center prong to right prong and center prong to left prong.

On the tail light plug, I'm reading voltage when the acc is on, but can't really tell which of the prongs is working since it has 4 prongs and is hard to reach with my meter probe. My wire colors are not the same as you described.

I can plug in both the fender tip light and the brake light and neither will come on with just turning in the acc switch to on. However, both will light up and work as brake lights when the acc is on and brakes are on.

Are there fuses somewhere else besides left side that might be blown?

 

start at the plug under the seat and work back.

if you see violet and brown wires, they are for the turn signals.

and a trouble light may be a better tool to use than a meter...a meter may show "voltage" but at close to zero current


Mike

 

Found it!!

It was a left side fuse "lights" that checked ok with my ohm meter, but was clearly blown once I pulled it. I replaced it with the spare and all is well.

Thanks mkguitar for helping me troubleshoot this thing.

 

You must learned you cannot ohm a fuse while it is in the circuit. You were measuring the resistance of the rest of the circuit. Glad you found it.

 

Yep... that was my lesson learned for the day. For some reason, I was thinking I could check resistance that way. I thought I had done it like that in the past, but I guess not. I was just ticked at myself for absentmindedly plugging in the light with the power on.

 

Lots of people check fuses with them in place. I`m an industrial maint mech and i got burned by that many, many years ago. I looked really stupid in front of alot of people! Now i always pull fuses to check.