Circuit Breaker Question

[woodside4032]

The previous owner relocated the battery to the trunk. I would like to put in a type 3 manual reset circuit breaker. Question is how do I figure out what size amperage I would need.

 

Thank you

Kevin :blink:

[banzai510(hainz)]

circut breaker for what?The starter?

 

Or circut breaker fuse box?

[woodside4032]

Yeah sorry I missed that in my first post. I want the circuit breaker in line on the main 1/O gauge cable to the starter.

[datsunaholic]

Oh, 500 Amp should be enough. Probably draws under 250 on a good day through.

 

There's a reason they aren't fused at the factory. The starter draw is variable (temperature, battery condition, load, etc).

[]2eDeYe]

I use a 100amp fuse for the main power supply in my CJ.

 

The biggest draws are on startup of your electrical devises. Find out your largest loads and size accordingly.

 

or...

 

I figured my alt is a 90 amp unit so 100 amp should pop if anything fries. So far so good.

 

Edit: My starter is not fused, as Holic stated they pull some pretty big amps. Make sure your cable is well insulated and isolated from any sharp objects and you should be fine.

[zetozeto99]

C-C-C-C-COMBO BREAKER!!!!

 

 

 

 

 

 

 

Oh wait you said "circut" breaker....?

 

:confused:

[woodside4032]

2eDeYe;175177']I figured my alt is a 90 amp unit so 100 amp should pop if anything fries. So far so good.

 

 

I was kinda thinking that but thought thats too easy, maybe not

[banzai510(hainz)]

Im still not getting this as the battery needs a certain about of current.

Batteries are rated a CCAs and some battery are up to 1000CCAs.

 

colder the motor and thicker oil. and other variables will determine how much is needed to start the car.

 

Now I can see putting a circut breaker / newer type plug in Fuse as the fusable link but by then whats wrong what was already in there.

If anything put a solid state volt reg or a internal volt reg alternator and a volt gauge in the car first and most troubles will be caught.

 

But heres something I found for you if you just got to have one

http://www.datsport.com/Battery_box.html

looks like a Ford starter relay to me

[datzenmike]

Run your starter cable through a length of garden hose for extra scuff resistance.

 

The fuse size is determined by the size of the wire or cable it protects. The positive cable to the starter doesn't have a fuse/circuit breaker so I wouldn't bother either. Make sure that the cable is well protected and insulated and you shouldn't have any worries. The 510 has a fusible link connected to the pos. terminal of the starter that feeds the fuse box. Why not just leave it... it works fine and almost never blows. If you are set on a circuit breaker, install it here and remove the fusible link. Unless you are having a constant problem with blowing the fusible link then a circuit breaker is just going along for the ride.

[thisismatt]

You should have a fuse, breaker, or at least a starting relay on your main power wire (within 12 inches of the battery is the rule of thumb). If you short that 1/0 (one zero, same as just saying 0ga) you have a very good chance of setting your car on fire without one. You could run the 1/0 to your starter using a dedicated starter relay that only engages the 1/0 for starting and piggyback a smaller, perhaps 4ga, run to power everything else with a fuse on the 4ga and no fuse on the 0ga, but that way the 0ga is only engaged at starting.

Edited June 24, 2009 by thisismatt

[woodside4032]

Thanks for all the help. I don't have any electrical problems. My main concern is the positive wire shorting out. Thats why I thought circuit breaker to cut the power in case of a short. Only as a precautionary measure. The hose idea sounds pretty cool.

[Z-train]

Battery disconnect switch.

[72240z]

Battery disconnect switch.

 

What if someone isn't there or capable of hitting it? If auto wouldn't that essentially be the same as a breaker?

[mklotz70]

Datzenmike and thisismatt make good points.

 

The point of the fuses/circuit breakers are to protect the vehicle....not the devise they power. If the devise or the wire shorts out, the fuse shuts off the power to that wire to help stop any fire hazard.

 

I'd consult some of the stereo sites and/or stores for they're recommendation.....they work with remote batteries and circuit breakers all the time.

[Z-train]

THere is no need to have a breaker on the starting circuit:confused:.I've haven't seen one in 40+ years of wrenching.Done right,positve cable routing will be bullet proof.I have three veicles with battery switches on them and i don't lose a minute of sleep over ANY scenario.

[Z-train]

What if someone isn't there or capable of hitting it? If auto wouldn't that essentially be the same as a breaker?

 

What could be happening without human interaction to cause the need?

[Beau M]

Mice.

[datzenmike]

Act of God... tree falls across car. But yeah, never seen a factory breaker/fuse between starter and battery. It just isn't needed. Just be sure it's well protected and doesn't rub anything. As I said, run the cable through a length of garden hose.

[Z-train]

Mice.

 

Sorry,No sale.I live in pak-rat heaven.I've never seen a battery cable chewed.And besides,say if a cable does get chewed,it is NOT going cause an issue sitting there.Vehcles don't short out and burst into flames just sitting there.ALso,mice/Pack rats don't move in over night.The vehicle has to be sitting for a while.

 

ANd if you are that paranoid about the furry little bastards,do what Mike said(i think it was Mike)run the cable thru a piece of hose.

[72240z]

I have seen mice do a lot. Squirrels chew through power lines, cable wires etc all the time. Not saying they will but an animal chewing through a bat cable wire shouldn't be counted out as impossible imho.

 

Besides that and an act of god though which are good points.

What I was thinking about was an accident where the driver is incapacitated.

 

I don't see a breaker being needed either for reasons already mentioned, but if I was going to add something inline it would be something automatic. Because some of the one in a million things that it would be useful for involve things being out of my control.

Edited June 24, 2009 by 72240z

[banzai510(hainz)]

Vehcles don't short out and burst into flames

 

he really has a Pinto!

 

 

Be honest the battery is more likely to short out due to a Bungy cord being used as alot of datsun onweres use them. Battery flys into hood or strap fails in truck and battery rolls over.

[Z-train]

I have seen mice do a lot. Squirrels chew through power lines, cable wires etc all the time. Not saying they will but an animal chewing through a bat cable wire shouldn't be counted out as impossible imho.

 

Besides that and an act of god though which are good points.

What I was thinking about was an accident where the driver is incapacitated.

 

I don't see a breaker being needed either for reasons already mentioned, but if I was going to add something inline it would be something automatic. Because some of the one in a million things that it would be useful for involve things being out of my control.

 

 

20 years in the CATV business,i've seen squirrels do plenty.However,we're not talking about squirrels.If these were such a needed item,then how come no car on the planet comes with one?

 

 

Vehcles don't short out and burst into flames

 

he really has a Pinto!

 

 

Be honest the battery is more likely to short out due to a Bungy cord being used as alot of datsun onweres use them. Battery flys into hood or strap fails in truck and battery rolls over.

 

 

True.And that whole Pinto thing was a scam by "Nader-types".

[datzenmike]

Be honest the battery is more likely to short out due to a Bungy cord being used as alot of datsun onweres use them. Battery flys into hood or strap fails in truck and battery rolls over.

 

Dude, embarrassing to admit but I did this in the early '80s with my 521. Twice! The first time it caught fire, both times the throttle cable was the ground return to the block and welded it solid... no gas peddle. After the first time I figured it would never happen again... wrong. Fixed the throttle... twice!! and bolted the battery down .. once. Just like the young guys on here!!! :o :lol::lol::lol:

[Z-train]

Dude, embarrassing to admit but I did this in the early '80s with my 521. Twice! The first time it caught fire, both times the throttle cable was the ground return to the block and welded it solid... no gas peddle. After the first time I figured it would never happen again... wrong. Fixed the throttle... twice!! and bolted the battery down .. once. Just like the young guys on here!!! :o :lol::lol::lol:

 

You are no longer "DatzenMike".You are now"Mike-the-Welder".:lol:

[72240z]

20 years in the CATV business,i've seen squirrels do plenty.However,we're not talking about squirrels.If these were such a needed item,then how come no car on the planet comes with one?

 

I don't see a breaker being needed either for reasons already mentioned, but if I was going to add something inline it would be something automatic. Because some of the one in a million things that it would be useful for involve things being out of my control.

 

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