A maze with no exit (brake light wiring)

[Cormanus]

Thank you Lord Popgun. :worship: Although with you electrical mastery perhaps we should call you Lord Voltemort.

 

[peterbaron]

Thank you Lord Popgun. :worship: Although with you electrical mastery perhaps we should call you Lord Voltemort.

Lord Popgun would be more proud with Lord Voltemort-Bakelite

 

[Lord Popgun]

Man, I loved the old Simpson 260 Bakelite multimeters. Rounded corners and all.

Some newer 260's have plastic cases with 90 degree corners. Some are like the old ones, but the case may be plastic. IDK.

As good as digital meters are, there are times when a good analog meter is needed, even when troubleshooting motorcycles

 

[peterbaron]

I know exactly what you mean, my Lord
How you keeping up, otherwise??

 

[misterprofessionality]

update, i've attached the ground to the housing of the light and now found that i get a solid light when i turn on the bike. both filaments illuminated, and no flashing when i depress the brake. that can't be correct can it?

 

[pekingduck]

update, i've attached the ground to the housing of the light and now found that i get a solid light when i turn on the bike. both filaments illuminated, and no flashing when i depress the brake. that can't be correct can it?

Yes, working as it should. The original taillight ground was through the green in the harness. This now grounds through the metal taillight housing/steel fender/frame.
You don't have to use the green ground wire, but it definitely doesn't hurt.
Some aftermarket taillights use the green wire, but if you only have 2 wires, then it grounds through the bracket/fender/frame.

Is it one of these?

 

[Cormanus]

MrP do you mean both filaments are on all the time and nothing changes when you activate the brake? Doesn’t sound right.

 

[pekingduck]

update, i've attached the ground to the housing of the light and now found that i get a solid light when i turn on the bike. both filaments illuminated, and no flashing when i depress the brake. that can't be correct can it?

No, the two filaments should not be going on at the same time if the brake is not depressed. Just so we can see what you're up against, can you send a picture of how you have things wired? and of the light itself? and of the bulb and socket?

 

[Lord Popgun]

I know exactly what you mean, my Lord
How you keeping up, otherwise??

I’m doing good as I can. Still going to work, and the Navy has gone to 3 shifts to reduce the crowd where I work. Staying home other than that. Haven’t had the bike out yet. Still no TP at the grocery but I’m good

I’ve been keeping out of this thread as PD has it all under control!

 

[misterprofessionality]

to avoid wasting any more time: I've fiddled with the way the green wire was mounted and now it's illuminating in a predictable manner. There must have been some tomfoolery around how I had it clipped to the tail light housing. You see, I didn't want to solder anything or make any permanent connections until i was sure everything worked correctly, so i just sort of clipped the green wire to a bolt that held the bulb assembly into the steel housing of the light fixture. this produced the results i gave above. when i moved the green wire onto one of the bolts that attached the fixture to the fender (using a makeshift ring terminal), the bulb began to behave correctly. now the lower bulb filament is always on while the upper bulb filament flashes with the brakes. i soldered the rest of it together and have it all mounted now. done deal.

 

[Cormanus]

Good news, MrP. Nice diagnostic work, pekingduck.

 

[pekingduck]

That's great to hear! Thanks for letting us know the findings. As others have said, a good ground is essential. Had me really scratching my head.

 

[Lord Popgun]

Good going MrP!! :banana: And great explanation w/pics PD

 

[Houtman_imp]

With all the praise Popgun is getting he still remains grounded....

 

[Cormanus]

Careful, Houtman, too much praise will give him a charge.

 

[peterbaron]

With all the praise Popgun is getting he still remains grounded....

....p e r m a n e n t l y... and therefore his conductivity = 0 Ohms (perfect)
This is why, we call him Lord.