The Ford Barn

Tinker · 10-22-2015, 11:14 AM

I have a Circuit breaker? and Resistor unit that I have a question about.

I don't have a question about the resistor but where the fuse usually is (32-39 i believe) there is a metal box, which I'm assuming is a circuit breaker.

Is there an advantage to this design? Is there possible issues with them? What years were they used?

Thank you

V8COOPMAN · 10-22-2015, 11:29 AM

Circuit breakers have the ability to re-set themselves, where-as when a fuse blows........well, there's no doubt the lights will not be operating again 'til the fuse is replaced. DD

Tinker · 10-22-2015, 11:39 AM

Just curious, how do they reset?

At what amperage do they cutout?

castiron · 10-22-2015, 11:41 AM

I think by cooling down.

tubman · 10-22-2015, 11:42 AM

They contain a bi-metallic strip that bends when it heats up and breaks the contact. When it cools back down, the strip straightens back out and re-establishes contact.

Bruce Lancaster · 10-22-2015, 11:53 AM

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...so, if your headlight circuit overloads the thing you get a flashing view of the world while you get stopped rather than utter instant darkness.

Tinker · 10-22-2015, 12:13 PM

Disco driving!

Thanks guys, I guess to test to see if it works correctly I'll have to add amps till it overheats.

JSeery · 10-22-2015, 03:21 PM

Don't know the amperage for the CB off the top of my head, but it should be in the same range as the fuse was, it is protecting the same wiring.

Edit: The CB first appear in the wiring diagrams in 40, but don't have any idea when in the model year it was, late 1939 models or from the start of the 1940 models.

39topless · 10-22-2015, 03:43 PM

Mine (1939) calls for a 30 AMP fuse.

bbrust · 10-22-2015, 06:02 PM

The 39 Deluxe that I'm working on has the CB.

CarlG · 10-22-2015, 06:16 PM

On my '92 Explorer, the turn signal circuit kept blowing. Even had a mechanic look at it to see what was the cause. After the 3rd or 4th time, he said I could continue paying him $85/hr to find the culprit, or I could put in a circuit breaker for $10 or so. It's been about 10 years and still working like a champ.

Tinker · 10-22-2015, 08:00 PM

Quote:

Originally Posted by bbrust

The 39 Deluxe that I'm working on has the CB.

The one I posted came out of a friends 39 truck. It had a 59a motor so was curious. The CB is original to the truck then I'd bet 10 too 1.

Thanks for everyone's input.

10-22-2015, 11:29 AM	#2
V8COOPMAN Senior Member Join Date: May 2010 Location: East Shore of LAKE HOUSTON Posts: 11,106	Re: Circuit breaker? & Resistor unit Question Circuit breakers have the ability to re-set themselves, where-as when a fuse blows........well, there's no doubt the lights will not be operating again 'til the fuse is replaced. DD __________________ *Click Links Below* __ ▼ *'35-'36 W/8BA & MECHANICAL FAN* *T5 W/TORQUE TUBE*

10-22-2015, 11:39 AM	#3
Tinker Senior Member Join Date: May 2010 Location: MN Posts: 7,053	Re: Circuit breaker? & Resistor unit Question Just curious, how do they reset? At what amperage do they cutout?

10-22-2015, 11:41 AM	#4
castiron Member Join Date: May 2012 Location: Sweden Posts: 31	Re: Circuit breaker? & Resistor unit Question I think by cooling down.

10-22-2015, 11:42 AM	#5
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,303	Re: Circuit breaker? & Resistor unit Question They contain a bi-metallic strip that bends when it heats up and breaks the contact. When it cools back down, the strip straightens back out and re-establishes contact.

10-22-2015, 11:53 AM	#6
Bruce Lancaster Member Emeritus Join Date: May 2010 Location: Madison, NJ Posts: 5,230	Re: Circuit breaker? & Resistor unit Question Sponsored Links (Register now to hide all advertisements) ...so, if your headlight circuit overloads the thing you get a flashing view of the world while you get stopped rather than utter instant darkness.

10-22-2015, 12:13 PM	#7
Tinker Senior Member Join Date: May 2010 Location: MN Posts: 7,053	Re: Circuit breaker? & Resistor unit Question Disco driving! Thanks guys, I guess to test to see if it works correctly I'll have to add amps till it overheats.

10-22-2015, 03:21 PM	#8
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: Circuit breaker? & Resistor unit Question Don't know the amperage for the CB off the top of my head, but it should be in the same range as the fuse was, it is protecting the same wiring. Edit: The CB first appear in the wiring diagrams in 40, but don't have any idea when in the model year it was, late 1939 models or from the start of the 1940 models. Last edited by JSeery; 10-22-2015 at 03:27 PM.

10-22-2015, 03:43 PM	#9
39topless Senior Member Join Date: Sep 2013 Posts: 1,027	Re: Circuit breaker? & Resistor unit Question Mine (1939) calls for a 30 AMP fuse.

10-22-2015, 06:02 PM	#10
bbrust Senior Member Join Date: Mar 2011 Location: Greencastle, PA Posts: 227	Re: Circuit breaker? & Resistor unit Question The 39 Deluxe that I'm working on has the CB.

10-22-2015, 06:16 PM	#11
CarlG Senior Member Join Date: Nov 2010 Location: Anchorage, Alaska Posts: 9,115	Re: Circuit breaker? & Resistor unit Question On my '92 Explorer, the turn signal circuit kept blowing. Even had a mechanic look at it to see what was the cause. After the 3rd or 4th time, he said I could continue paying him $85/hr to find the culprit, or I could put in a circuit breaker for $10 or so. It's been about 10 years and still working like a champ. __________________ Alaskan A's Antique Auto Mushers of Alaska Model A Ford Club of America Model A Restorers Club Antique Automobile Club of America Mullins Owner's Club