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This is an item that has been talked about in the past, old circuit breakers in the M37. I soldered some of the wires into the pins(or what ever they are called) on the end of the headlight wires. I wasn't too keen on this method, I liked the crimp better. So I took the plunge and purchased the crimp tool. I completed the rest of the connections with the crimp tool. OK to my point. After a local car/truck show the M and I got caught in a nasty rain storm. I lost the light circuit. No head lights or tail lights. Every so often I would hear a clicking noise(yes even with all the noise in the M ). When I got home I turned the light switch off and on and heard the click again.I figured with the hood up and it raining hard, water got into something. It shouldn't all the connections are water tight.I disconnected wires to the headlight on the drivers side and checked them with the ohm meter, dead short.Next went to the passenger side and I could see where the shell was darkened from an arc, took it apart. The solder had a little point sticking out that made contact with the shell which in turn made contact with the metal clip, tripping the 63 year old circuit breaker repeatedly.It would trip cool down and trip again all the way home. I removed the pin with the solder and installed a new crimped pin. The M37 traveled about 60 miles before this happened, it was just enough vibration to have the solder point make contact. The 60 miles I'm talking about is the total mileage from the time I completed the restoration to the time the circuit breaker tripped. Yes Bob as we talked about the old circuit breakers they do work. I had talked to Bob about this issue a while ago. As long as the circuit breaker wasn't corroded and look to be in good shape it should perform it's function.

Hi Ed,

Sounds like an interesting adventure you had there. And thanks for explaining to me HOW those circuit breakers work. Glad to see they stood the test of time!

regards,
bob

I love the circuit breakers over fuses. no time to change a fuse when getting shot at!

w30bob wrote:Hi Ed,

Sounds like an interesting adventure you had there. And thanks for explaining to me HOW those circuit breakers work. Glad to see they stood the test of time!

regards,
bob

Bi-Metallic spring contact is the usual method in these types of breakers, in a state of too much current flow the length of the breaker contact becomes too hot resulting in the 2 different metals in the contact "arm" to expand at different rates, this in turn causes the arm to flex in the opposite direction to it's sprung tension until it over centres and flips away from the output contact thus breaking the circuit. Once the arm cools down the metals in the arm contract back to their original length causing the arm to flip back onto the output contact and thus reconnect the circuit, the arm "over centring" back and forth is what gives the breaker the click sound it makes, spring assisted units tend to make a bit of a "ping" sound as the spring will oscillate with the switching action....
Clear as mud??

MM