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Kestrel

Replacing thermo circuit breaker w/ fuse, '51 Super

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I just read in the December Bugle that a member replaced the old stock thermo circuit breaker in the lighting switch with a modern 30 amp fuse in his '37 Buick for safety reasons.

I want to do the same for my '51 Buick Super. Could anyone advise what terminals to connect the leads of such an in-line fuse ?  Or perhaps simply splice the in-line fuse into the hot wire before it attaches to the #1 terminal. Here's a photo of mine showing what I believe is accurately marked. Thank you !!

 

bottom right  says "#1 terminal, hot from battery"

IMG_0957.jpeg.6cf4f6f21405f02a6837a9e9f739e909.jpeg

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Right! Less safe when  you consider what having NO HEADLAMPS at night does to the car/driver control issue.😲

 

I was going to write a "sternly worded letter" to the editor about this. 

 

And especially since 30 amp automatic reset circuit breakers are available to do this job!

 

Here is just one example, posted as example, I have no knowledge of this vendor.

 

https://www.delcity.net/store/12V-Auto-Reset-Circuit-Breakers/p_198669.h_198847.r_IF1003?mkwid=s&crid=38094426869&mp_kw=&mp_mt=&gclid=EAIaIQobChMImKvDqY2p5gIVGIeGCh2ITwKWEAQYBCABEgITcPD_BwE

 

There is a GOOD reason vehicle manufacturers went to circuit breakers in headlamp circuits way back when, keeping fuses in the rest of the lighting circuits to this day. Do NOT be the guy who finds out why it was a good idea  at night  on a winding road......😉

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I understand that the circuit breakers fatigue with age.   Why can't a modern 12v circuit breaker be put in parallel with the old one or used to replace the old one.   Someone else can do the math to determine the correct breaker to use.   😊

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Hoping an  original 70 year old breaker to function as designed was my reason to replace it, not to mention my car has original head and tail light wiring running to both ends of the car. Everything works but it's not been thoroughly inspected.

 

 After reading the above, it might be wise to remove and test the original for proper function and/or install a modern 6v auto reset breaker in parallel, keeping the original. From reading the manual if an overload happened, my understanding is the head lights would flash on and off , keeping the wires cool enough, until the issue is resolved. It would be an interesting experiment. 😀

 

 

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Don't worry about fatigue with age unless it is kicking off. If it is kicking off, temporarily put an ammeter in series with it to make sure excessive current draw isn't to blame. If it is bad, replace it.

 

 

 

 

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Thanks Bloo. Sounds like a logical approach. I intend to clean and remove any corrosion from all terminals in the various circuits this winter. Inspect any visible insulation for chaffing as well.

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Change the wiring and you will not have to worry about fuses or circuit breakers...or don't drive at night.  Any wire with insulation missing will oxidize and have reduced load carrying capacity making the headlights too dim to drive at night anyway.  And I am the dumb bum that drove that way for years!:unsure:

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News Flash!

 

Breakers are rated in AMPS for when they open a circuit for protection of that circuit.

 

Breakers do have a voltage rating, so they will actually open a circuit and not just arc over inside keeping the power on.

 

BUT

 

There is no difference in 6 and 12 volt circuit breakers. Even 24 volt circuit breakers are the same. 32 volts is a typical next step up in voltage rating for fuses and breakers.

 

So buy that auto reset circuit breaker of recent manufacture, install in place of the 80 year old one and drive on happy.👍

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I just spoke with a rep from Y and Z's Yesterdays Parts https://www.ynzyesterdaysparts.com/  .  Surprisingly they carry an exact 6v GM factory thermo circuit protected lighting switch for these era Buicks. It has the same bi-metal strip, contact points, and the control shaft will accept my existing original knob. 

Thinking of asking Santa for that one. Not cheap at $95.00 but what heck, it's only money. Plus the corrosion on mine, even after cleaning, messed up the dimmer operation  🎅

IMG_0958.jpeg

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