Ironhead Circuit breaker

[HarleyAsh]

Is it possible to frazzle a circuit breaker? I have tested my coil and the leads and they seem fine (correct ohms) I have no spark at the plugs though the bike is turning over but just won't start

[Ferrous Head]

The circuit breaker is just an "on off" switch. When the points are closed current flows from the ignition switch to ground through the points,

If you have the points closed and the ignition switch on opening the points by hand (use a screwdriver to lift them open) you should get a small spark.

If you don't get a spark there you probably aren't getting voltage to the points. Check your wiring from the ignition switch.

[Gearhead88]

Yes , you can " frazzle " a circuit breaker , they are a thermal activated safety device , they reach a certain temp and open up , when they cool they close . This is if they are working correctly , for example , if a circuit , for whatever reason pulls too much current , the resulting heat will open the circuit breaker , protecting the wires and other components .
When it all cools down it will close the circuit and flow current again .
If a circuit breaker has been repeatedly run hot or near it's capacity , it is possible for it to weaken over time .

The coil will have voltage to it when the key is on and the kill switch is on , check the coil terminals for battery voltage .

The points are the ground side of the circuit , when the points are closed , the coil circuit is completed , a magnetic field is created , when the points open , the magnetic field that was present then collapses and there should be spark at the plugs.

[JB in NC]

Circuit breakers do seem to age out, somewhere between 25 and 40 years. They aren't watertight, so moisture in the air takes its toll over the years.

Jim

[Gearhead88]

Originally Posted by JB in NC

Circuit breakers do seem to age out, somewhere between 25 and 40 years. They aren't watertight, so moisture in the air takes its toll over the years.

Jim

True , where they are mounted plays into the length of time they might last . I've changed several on customers bikes that had failed from water intrusion .

[Ferrous Head]

Of course. Circuit breaker. It's a late model "thingy" with electric start and circuit breakers. I was thinking you were referring to the points.

With the later bikes and tiny little handlebar switches more can go wrong. The tiny wires to the switches control a relay which is connected to higher gauge wiring. The handlebar switch can die. The relay can die. The wiring between them can die. The circuit breaker can die. The wiring to the circuit breaker \can die.

None of this happens to my magneto fire \d bikes of course.

It is easier to check "backwards" from the points though. The last place you want to look is inside that handlebar switch. They are simply a nightmare.

[Ferrous Head]

I also love the flash cans in the headlight. You know, those things that fall apart at the touch of a button.

[kitabel]

To test the breaker, briefly jump it out.