The Ford Barn

Bill in Al · 08-31-2011, 05:12 PM

My '41 tudor, all stock electrics, 6V, V8 is tripping the headlight circuit breaker after the lights are on for about 30 seconds. It first started with bright beam only but now it trips with either hi or low beam when the engine is at highway speed. The lights aren't abnormaly bright when this happens and the ampmeter looks normal. What should I look at and in what order?

47COE · 08-31-2011, 05:30 PM

It could be the circuit breaker getting tired and tripping at a lower current.

Does it happen only when on the road at highway speed, or can you make it happen while parked and the engine revving? If the former, perhaps a wire has missing insulation and is shorting out from vibration.

Tom

rotorwrench · 08-31-2011, 06:18 PM

If it was a direct short, the breaker will pop imediately. If it is slow to pop, it likely is the breaker going south. They are a heat sensitive bi-metalic strip that can lose its temper after many years and probably a few trips here and there. A corroded or dirty ground path on a high current draw system like the head lamps can also create enough heat over time that it could trip an old breaker. The old cloth covered wire can give a lot of troubles if it's starting to deteriorate too much.

Kerby

Rich Overton · 08-31-2011, 06:36 PM

Back in 1951-'52 my '40 Merc coupe did it quite often. Usually at the most inconvenient times. I replaced the breaker. No more problems. Could be other things as the guys mentioned but I do remember them getting "tired."

Rich.

Bill in Al · 08-31-2011, 06:37 PM

Thanks guys,my thoughts too about the breaker.It'll trip at speed on the road or stopped at a fast idle. I didn't know it was a strip, just assumed it was a winding of some sort. It'll be nice to travel after nightfall again!! --Bill

quickchange34 · 08-31-2011, 09:12 PM

Sponsored Links (Register now to hide all advertisements)

The more a circuit breaker brakes the less amp load it takes for it to break again. Replace the breaker.

Bill in Al · 09-07-2011, 06:51 PM

Changed out the old breaker with one from Shelly Vanpelt and now the lights stay on! Thanks everyone for your help.--Bill

johnny · 09-07-2011, 07:22 PM

How about disconnecting one light at a time and see if it still does it ,shoud it do it with one but not the other then likely a prob. with the light.

08-31-2011, 05:12 PM	#1
Bill in Al Senior Member Join Date: May 2010 Location: Pell City (New London) Al Posts: 317	Headlights are tripping circuit-breaker My '41 tudor, all stock electrics, 6V, V8 is tripping the headlight circuit breaker after the lights are on for about 30 seconds. It first started with bright beam only but now it trips with either hi or low beam when the engine is at highway speed. The lights aren't abnormaly bright when this happens and the ampmeter looks normal. What should I look at and in what order?

08-31-2011, 05:30 PM	#2
47COE Senior Member Join Date: Apr 2011 Location: Oregon Posts: 220	Re: Headlights are tripping circuit-breaker It could be the circuit breaker getting tired and tripping at a lower current. Does it happen only when on the road at highway speed, or can you make it happen while parked and the engine revving? If the former, perhaps a wire has missing insulation and is shorting out from vibration. Tom

08-31-2011, 06:18 PM	#3
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,425	Re: Headlights are tripping circuit-breaker If it was a direct short, the breaker will pop imediately. If it is slow to pop, it likely is the breaker going south. They are a heat sensitive bi-metalic strip that can lose its temper after many years and probably a few trips here and there. A corroded or dirty ground path on a high current draw system like the head lamps can also create enough heat over time that it could trip an old breaker. The old cloth covered wire can give a lot of troubles if it's starting to deteriorate too much. Kerby

08-31-2011, 06:36 PM	#4
Rich Overton Senior Member Join Date: Jun 2010 Posts: 135	Re: Headlights are tripping circuit-breaker Back in 1951-'52 my '40 Merc coupe did it quite often. Usually at the most inconvenient times. I replaced the breaker. No more problems. Could be other things as the guys mentioned but I do remember them getting "tired." Rich.

08-31-2011, 06:37 PM	#5
Bill in Al Senior Member Join Date: May 2010 Location: Pell City (New London) Al Posts: 317	Re: Headlights are tripping circuit-breaker Thanks guys,my thoughts too about the breaker.It'll trip at speed on the road or stopped at a fast idle. I didn't know it was a strip, just assumed it was a winding of some sort. It'll be nice to travel after nightfall again!! --Bill

08-31-2011, 09:12 PM	#6
quickchange34 Senior Member Join Date: May 2010 Location: charlottesville, Va. Posts: 589	Re: Headlights are tripping circuit-breaker Sponsored Links (Register now to hide all advertisements) The more a circuit breaker brakes the less amp load it takes for it to break again. Replace the breaker.

09-07-2011, 06:51 PM	#7
Bill in Al Senior Member Join Date: May 2010 Location: Pell City (New London) Al Posts: 317	Re: Headlights are tripping circuit-breaker Changed out the old breaker with one from Shelly Vanpelt and now the lights stay on! Thanks everyone for your help.--Bill

09-07-2011, 07:22 PM	#8
johnny Senior Member Join Date: May 2010 Location: London On, Can. Posts: 377	Re: Headlights are tripping circuit-breaker How about disconnecting one light at a time and see if it still does it ,shoud it do it with one but not the other then likely a prob. with the light.