question for lucky 13

[BILLY T]

hi,
i was following one of your post about your electricial system.
you said, you put in a breaker switch that connects to battery.
i was wondering where you purchased it. sounds light a good idea.
i have a 1966 coupe with no electricial protection.
thanks much,
bill

 

[paul67]

I am interested in this as well. Hope he comes back with the info.

 

[Tom Bryant]

I think John answered your question here in post 4. But it sounds like John is saying that '67 and newer have this protection already.

Billy T,

Welcome to the CAC.

Tom

 

[LUCKY13]

Electrical breaker for 65

The part number at NAPA is 782-3039. It is a 150 amp breaker with a manual reset (no fuse).

 

[JohnZ]

The part number at NAPA is 782-3039. It is a 150 amp breaker with a manual reset (no fuse).

I'm confused :confused - where do you plan on connecting a 150-amp breaker? What are you trying to protect?

 

[LUCKY13]

I'm trying to protect against a dead short. Several years ago, something happened (still don't know what) and my wiring between the switch and the starter was fried. This small breaker (1.5" X 2") is now mounted on my firewall between the battery and the starter. It will provide some protection for my wiring, should another short occur. It was inexpensive and it may never help me but it feels good for me to know it's there.

 

[Pseudomind]

And if done right could serve as a simple method of a simple anti-theft device, park,open the circuit, no start.

 

[paul67]

I'm a little confused as well. What on the car can generate 150 amps? My alternator is 37 amps.

 

[LUCKY13]

During the actual "starting process" the amps are high, hence the large size of the battery cables.

 

[paul67]

Thanks. I missed the obvious! My battery is 850 CCA (cold cranking amps). Do you have a pic of the breaker?

 

[JohnZ]

I'm trying to protect against a dead short. Several years ago, something happened (still don't know what) and my wiring between the switch and the starter was fried. This small breaker (1.5" X 2") is now mounted on my firewall between the battery and the starter. It will provide some protection for my wiring, should another short occur. It was inexpensive and it may never help me but it feels good for me to know it's there.

A 150-amp breaker between the battery and starter will trip the first time you start the car - the starter will draw from 250-400 amps when cranking. The circuit you REALLY want to protect is the 10- or 12-ga. main power feed from the battery (at the starter solenoid battery cable stud), which feeds the horn relay (which is the main power junction for the whole car). That's the wire that has the fusible link from the factory starting in 1967. That big breaker at the battery won't keep any harness from frying - with a dead short, they'll melt long before the breaker sees anywhere near that kind of current - that's what the fusible link protects from happening.

 

[LUCKY13]

I just completed a complete rebuild on the engine and I've started it 15 -20 times without the breaker tripping. I'm just an ordainary guy who likes old cars. I never worked for Zora either. I'm trying to help whoever I can on this site, even though I'll never claim to be an expert at anything. Sorry if I ruffled your feathers John.

 

[JohnZ]

I just completed a complete rebuild on the engine and I've started it 15 -20 times without the breaker tripping. I'm just an ordainary guy who likes old cars. I never worked for Zora either. I'm trying to help whoever I can on this site, even though I'll never claim to be an expert at anything. Sorry if I ruffled your feathers John.

No ruffled feathers here at all - just trying to understand your setup.