[TecniColur]

I recently changed the battery on my newly acquired 1975 cb500t and I noticed smoke coming from an electrical connector. I've since identified the source as the rectifier/regulator, but while searching I saw this little box dangling down under the electrical compartment. Any idea what it could be?

 

[450k4]

Not sure, but looks like the flasher unit for the turn signals. If you can get the rubber sleeve off w/o destroying it there might be indications on the metal can.

SteveG

 

[WintrSol]

Or, it could be a diode. I don't have your schematic, but you should find it there by the wire colors. I would expect the flasher to be up front, near the coils.

 

[TecniColur]

Thank y'all so much for the advice! I'll check the wiring diagram I have and see if I can identify it.

 

[Boomer343]

Looks the same as every other signal flasher I've seen on this vintage of Honda.

If your wiring from the voltage reg is smoking most often it is from poor connections overheating and burning wires. It needs to be checked very carefully and repaired properly.

 

[middletons]

I’m with Boomer, its a flasher. They can be at the front by the key switch, or back by the battery.

 

[TecniColur]

Looks the same as every other signal flasher I've seen on this vintage of Honda.

If your wiring from the voltage reg is smoking most often it is from poor connections overheating and burning wires. It needs to be checked very carefully and repaired properly.

The ground wire leading to the rectifier/regulator is all sorts of burnt, I've got a new rec/reg coming from common motors that comes with new wiring and connectors. I'm also gonna clean up the frame ground.
Do you think it would be good to take out the main harness and check it for shorts as well?

 

[Boomer343]

The ground wire leading to the rectifier/regulator is all sorts of burnt, I've got a new rec/reg coming from common motors that comes with new wiring and connectors. I'm also gonna clean up the frame ground.
Do you think it would be good to take out the main harness and check it for shorts as well?

Yes, most definitely. I would suggest checking with Sparck Moto and see if they have a replacement harness for your bike. They can do one offs or modify a harness from a similar bike.
Common Motors is quite expensive for parts so you should check around to places like 4into1 for parts.