Re: Starter Button and General Wiring Questions - 1941 Packard 110

Posted by HH56 On 2014/8/13 15:28:35

Packard calls it thermal protection. In modern terms it is a self resetting circuit breaker. If you look at the switch you will see a strip of metal running down the center for about half the length of the switch and between the side wire terminals. One end is connected to the switch fiber board and internal contacts and the other end stops below a small screw. That is a bimetallic strip which heats with current and bends. When a short or excess current causes it to reach the set point controlling the amount of bend, connection breaks and power is cut. When power is cut, strip starts to cool and eventually makes the connection again. That is the cycling part. It will continue cycling until the problem is corrected or the strip and contacts fail.