Headlight Circuit Blowing Fuse 73 GT250

[sethrobb16]

I have recently upgraded my rectifier and replaced it with a tympanium rectifier/regulator. It is working well and keeps my charging system in a good voltage range. That being said, whenever I flip my headlights on, my fuse blows every time. What is the most likely culprit here? Does anything other than the head lamp circuit run through the headlight switch? I rewired the one charging coil that ran through the headlight switch to be on all the time. Other than that, I did not change any stock wiring.

Could this be an issue with the wire harness that runs behind the battery box? or is the problem most likely behind the headlamp?

Also, if anyone has a 1973 GT250k wiring diagram in high resolution, that would be a great help!

Thanks!

[jabcb]

How does your rectifier/regulator wiring compare to my diagrams?

You may have a short in the headlight circuit that is unrelated to the regulator/rectifier upgrade.

[sethrobb16]

I think it is unrelated to the rectifier. I used your recommended diagrams to wire up the rectifier, so I bypassed the switch for the lights on coil.

For the headlight circuit, what should I be checking that would cause a short?

[jabcb]

Had a T500 wire near the battery box with damaged insulation from the decades of history.

Check the headlight & taillight wiring. Look for damaged insulation and connector issues.
Try disconnecting stuff to see if the problem continues: no taillight, headlight connected but not installed, and no headlight.

Do you have a multimeter?

[sethrobb16]

Ok I will try to disconnect the headlight and isolate the tail light and vice versa to see exactly where the issue is. From there, I will check wires and check for damaged insulation or connections once I know exactly where the short circuit is coming from.

Yes I have a multimeter