Mystery??

[clf]

In this instance I would urge you to pull out the LSM and check it. There is one instance I recall of a 75 catching fire on the road with the source stated to be the LSM, and they are known to corrode (visible through the casing).

To check the wiring in my picture above, you really need to remove the bumper and headlight, but you may be able to feel if the wiring is damaged by sliding your hand between the headlight and the chassis leg. But this will likely only result in a failed bulb.