I'm planning out an anti-theft kill switch system for my truck that works on a "secret code," i.e, certain switches have to be in a certain position for the truck to run. Obviously it doesn't behoove me to go into too much detail, but part of my plan involves a switch that, when the thief sets it to the wrong position, will cause a short and trip a circuit breaker.

The easiest way to arrange this would probably be to replace one of the maxi fuses with a manual-reset breaker designed to fit where the fuse goes. But there's a catch: the 20-amp maxi style breakers that I've found have interrupt ratings of around 150-300 amps. If I just wire the switch with a dead short, the breaker will have to interrupt more than 2000 amps (two batteries in my diesel) and probably wreck the breaker.

I think I need a dummy load that will limit the current to somewhere between 30 and 150 amps: enough to trip the breaker but not enough to fry things. Anyone got ideas of what I could use for a dummy load?

 

Even making the breaker trip on a overload is going to be hard on it. It will probably be a breaker you need to depend on for some critical circuit, since you are using it to stop the vehicle? I would think of something different besides tripping a breaker.

 

My best description for the idea of a circuit breaker is "ill-conceived", to put it politely.

 

A safer idea would be for a switch in the wrong position to disable the fuel injector circuit and sound an alarm at the same time. No one is going to want to hang around to try and diagnose it.

 

AeroElectric Connection - Breakers not Recommended for Aircraft

Service Life Evaluations of Low-Voltage Power Circuit Breakers