Q: Headlights not working in 1980 Cadillac Eldorado

Is it just your headlights that won’t come on? Is it both the high and low beam light on both sides? It is important to note that most cars now have a fuse for each individual headlamp bulb, so checking fuses would be a good place to start, and then the bulbs themselves. If after checking the fuses and bulbs you still have not found the problem it may be time to seek outside help. You have to be extremely careful when checking electrical problems on your car, a lot of people will use a test light not knowing that when they do so they are actually adding to the circuit every time they probe a wire with that test light grounded to the chassis. This may not sound like a big deal, but in a parallel circuit it causes amperage to increase which can cause some serious issues. Without a voltmeter, wiring diagram and some formal training in electronics, I strongly advise leaving it to a professional mechanic such as the one from YourMechanic. They will be able to diagnose your headlights and come up with the correct repair.