The other night the wife and I were out for a drive in our 72 cougar XR7 convertible and it got dark out so I turned the headlights on. Since for some reason my high beam/ low beam indicator on the dash hasn’t worked for years. That’s a different story.
So when I turned on the headlights I don’t know if I have I’m high or low beams on as my lights are an old upgrade that wasn’t very good years ago. But anyways. After driving for a short distance the headlights started flashing on and off. But if I click the foot pedal to change it. They would stay on. And it turns out it’s the high beams that are cutting out. Before you blame the foot pedal. This issue happened to me before(few years back) And I replaced the switch out with a new one. Still did it. but since I never drive at night in the cougar. I never was a 911. But not it’s bothering me. I jut purchased new upgraded headlights to LEDs to see if that will fix the issue. Plus hopefully be able to see better at night.
Any idea’s what it could be. I have a new alternator and battery is good. Car start and runs like a dream
The headlight switch has an internal automatic resetting circuit breaker for the headlights. I would bet the problem occurred when the hi beams were on. If you used halogen replacement lights, they draw more current than the old sealed beam units and may trip the circuit breaker. If you put in LED lights, they typically draw far less current and the problem may go away.
With 70toy 100% - Presuming you changed the headlights to LED, but left the high beams as Halogens. I had the same issue when I bought my car and had to drive it home at night fall - the issue totally resolved when I went back to 4000/4001s. Easier than changing the harness.
I had that problem on the 71 XR-7 I had. It was fun driving it from Brian Aust’s house back into Salem back in 2017. That was the first time I had driven it after dark. A replacement switch fixed it. Oh, it still had incandescent lights in it.
Our old 56 chev had the brake lights going thru the hl switch. When i installed the halogen stop light bulb , it woud kick the circut breaker. Might chech and see what other devices go thru the hl switch
A relay harness for the headlights will also help. I had issues with my Hella H1/H4 halogen conversions tripping the factory breaker, but installing a relay harness for the headlights took care of the issue. Bonus: Dash lights were brighter too.
all I have to do is find out way my high/low beam light on the dash doesn’t work anymore. Bulb is good. I changed the dash because the circuit board or plastic was falling apart. And the light still doesn’t work