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I am just finishing the restoration of a 1931 Series 42 Sport Phaeton. For safety and peace of mind I am considering replacing the under dash circuit breaker with a fuse block. Not sure I want to trust an 80 year old safety device. Any thoughts or suggestions would be appreciated.
Thanks, Al
Al,
Been thinking about the response to this for a while. It would be nice for the other engineers to step forward with their thoughts on this as well.
Before I answer, let me explain I am an electrical engineer, master electrician, and an ASE master. I have worked as an expert witness on electrical cases involving electrical fires, lightning, and voltage surges. Electricity is nothing to play with, and it is always a good idea to take every precaution to ensure the system is as safe as possible.
Having said that, your question relates to the replacement of the circuit breaker(s) in your Pierce. Before I would think about the breaker, I would first determine the condition of the items the breaker is designed to protect, namely the wiring and devices being fed the electricity. Circuit breakers in the early ’30’s were rare. Most auto manufacturers used fuses, as they were cheaper. Even into modern times, autos are usually protected by fuses. Circuit breakers, then and now, were used to protect devices, such as headlights, that were essential to the car’s operation, and where the complete loss of the circuit could have disastrous results. Breakers in cars were designed to trip in an overcurrent condition, and reset after some period of time. This was often done using a bimetal strip, which curved in an overcurrent conditon, and reset after the metal strip cooled. It is the same design in a flasher.
Assuming the circuit breaker is for an essential circuit, I would first check the wiring and the device for wear and safety. If it is still good (and I have found in houses, for instance, that older “BX” wiring can hold up to surges better than the newer “Romex” wiring), then you may want to leave well enough alone for a show car or one in the HPOF class. Be sure to check the breaker to ensure it is working properly. I have seen instances where a breaker was used and a fuse was installed in series with it. The fuse was usually rated significantly higher, say 3 to 6 times the breaker rating, and was used to prevent shorts in the event of a failed breaker. The best situation would be to replace the wiring and breaker with correct reproduction wiring from a harness manufacturer.
If the car is a driver, I would replace the wiring with new wiring of the same or lower gage (wire with a smaller number is a larger wire that can handle more current) and a temperature rating as high as possible (90 to 105 degrees C). Make sure to replace it in the fabric sleeves Pierce used (available at Restoration Supply and other places), and check to see the wiring is not susceptible to wear or heat. I always try to solder connections instead of using crimps wherever possible.
Hope this helps!
Bob
Al,
To piggyback on Bob’s comments, contact Rhode Island Wiring (RIWire.com) and see what they have for you. They make cloth covered plastic covered wire that is very original looking. THey also make wiring harnesses for most classic cars.
Good luck on the project and I reiterate Bob’s position of keeping it original. You are trusting a good number of essential 80+ year-old systems, so don’t ditch the wiring system, which was probably one of the best made at the time. Remember, it is a Pierce-Arrow. You don’t run that much power through the lines, so don’t get too fancy.
Peter
I like the idea of a higher capacity fuse inline with the original circuit breaker, a very good idea to back up the older circuit breaker with a simple fuse. Just make sure the fuse is rated for more current than the CB.
Greg Long
What is described as a ‘circuit breaker’, is like nothing you have ever seen in your professional work! It is like a doorbell buzzer. When the current is two high the unit starts to buzz and momentarily breaks the circuit. The noise lets you know you have over run the systems capacity and keeps the wiring from over heatng. Of course the headlights will fliker but not go out.
Thanks Bob,Peter,Greg and Bill for the good information and suggestions. After some deliberation, I decided to leave the circuit breaker in place but bypass it with a new circuit breaker and junction block. This way I can forget about the old system and worry about other things. Given that they are up under the dash and virtually invisible takes care of the originality issue. On the subject of wiring and wire terminals, I am 100% in agreement with you guys. I have a new RI Wiring harness in the car. Great product and people. When I install new terminals on wire I first crimp them on with my “Knipex”” German made crimping tool. This makes the connection as one and also holds the terminal in place. Then I solder the connection and know that no one will ever have a problem with it.
Al Morkunas
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