Headlight

Another unbelievable !----------the op !
hey we all started somewhere. Most of us that was knowing little to nothing, whether we knew it or not.
I remember taking a headlamp into the parts store to get a replacement pair. The guy says, both lamps? are you sure its blown? Uh, well, uh, no I guess not. (I didn't own a Simson and certainly not Fluke or any other multimeter) The lamp I brought in tests fine. H'm. Go home and try the other lamp using the battery charger. Lights up. Wasn't the lamps at all - circuit breaker (yes, a'75 Valiant). Lesson learned because the store owners were helpful even to a dumass kid.

@Valsig66 Pishta makes a good point. The less resistance in the electric lines equals more voltage at lamps, and the brighter they will burn. If you want to walk through how to test, people here can help you do that. If you want a plug-in version of the relay setup that Pishta shows in the diagram. Rob (crackedback) makes a good quality one.