I was looking for the same thing, and then I remembered that there were circuit breakers available that would do the job. I found a handful at a swap meet for $5.

10, 15, and 20 amp.

Too many cars, too many parts, too little coin, too little space to work in, too little time left to make it all happen! Update: down to one ride, still too many parts, a little more jingle in the pocket, gaining space, and it's going to happen this year!