Battery To Alternator Fuse?

[dodge68charger]

Not On a Mopar But a General Wiring Question. ( No Starter Relay )

Im Running a 140 amp 1-Wire Alternator with a 4 Gauge Wire Going To The Main Starter Positive Terminal To The Alternator.

The Batterys In The Trunk.

I Also Wired My American Autowire Main Fuse Block Feed To The Main Starter Positive Lug.

Should I Add a Fusible Link Anywhere In Between?

Just Dont Want Anything To Catch Fire.

Thank You

 

[bearman]

Safety at any point is most important. Fuses, circuit breakers and relays help to protect from fire. The biggest thing I do is up the size on the wire. Example if the wire is a 12 gage I'll up it to carry the load easily. Everyone ups the Amp load at the alt but nothing to carry the new load. That is stress and heat so just remember every time you add something make sure your wiring will handle it. Just my thoughts

 

[pnora]

Not On a Mopar But a General Wiring Question. ( No Starter Relay )

Im Running a 140 amp 1-Wire Alternator with a 4 Gauge Wire Going To The Main Starter Positive Terminal To The Alternator.

The Batterys In The Trunk.

I Also Wired My American Autowire Main Fuse Block Feed To The Main Starter Positive Lug.

Should I Add a Fusible Link Anywhere In Between?

Just Dont Want Anything To Catch Fire.

Thank You

1-The alternator should have its own fuse of proper capacity.
2-The main feed to your American Autowire should also have its own fuse of proper capacity.

 

[R413]

Do people even know what a 125 amp alternator means?

Why do you think you need so much? More is not better here.

 

[RemCharger]

Do people even know what a 125 amp alternator means?

Why do you think you need so much? More is not better here.

It means you're carrying a spare welder in case of emergency?

 

[RJRENTON]

1-The alternator should have its own fuse of proper capacity.
2-The main feed to your American Autowire should also have its own fuse of proper capacity.

Alternator output connections to the vehicle's wiring system are not fused. If an alternator is disconnected, due to an open fuse or fusable link, while under load, it will damage the alternator's diodes, due to a high transient voltage surge. The alternators maximum current is limited by its internal impedance (quilivant to DC resistance) by design and components.
BOB RENTON

 

[pnora]

Alternator output connections to the vehicle's wiring system are not fused. If an alternator is disconnected, due to an open fuse or fusable link, while under load, it will damage the alternator's diodes, due to a high transient voltage surge. The alternators maximum current is limited by its internal impedance (quilivant to DC resistance) by design and components.
BOB RENTON

So what happens when an alternator shorts to ground internally?

 

[RemCharger]

Alternator output connections to the vehicle's wiring system are not fused. If an alternator is disconnected, due to an open fuse or fusable link, while under load, it will damage the alternator's diodes, due to a high transient voltage surge. The alternators maximum current is limited by its internal impedance (quilivant to DC resistance) by design and components.
BOB RENTON

You must mean older mopar wiring systems? Your 1st sentence is not correct in general.

 

[451Mopar]

Not On a Mopar But a General Wiring Question. ( No Starter Relay )

Im Running a 140 amp 1-Wire Alternator with a 4 Gauge Wire Going To The Main Starter Positive Terminal To The Alternator.

The Batterys In The Trunk.

I Also Wired My American Autowire Main Fuse Block Feed To The Main Starter Positive Lug.

Should I Add a Fusible Link Anywhere In Between?

Just Dont Want Anything To Catch Fire.

Thank You

Most new cars use a slow blow MEGA Fuse at the battery.
In the case of a shorted alternator, the short would prevent current from leaving the alternator, and the fuse at the battery would prevent the battery from supplying current to the short.

There is no fuse at the alternator. The alternator wiring should be sized to carry the alternators output.

From your wiring description, it sounds like you are not using a battery cut-off switch?

 

[pnora]

Alternator output connections to the vehicle's wiring system are not fused. If an alternator is disconnected, due to an open fuse or fusable link, while under load, it will damage the alternator's diodes, due to a high transient voltage surge. The alternators maximum current is limited by its internal impedance (quilivant to DC resistance) by design and components.
BOB RENTON

Bob all newer cars and trucks have the Alternator fused. I cant say when they started but I am sure there was good reasoning behind it. I respect your theory and logic. However I would rather a blown alternator than a wiring mess. I stand by my statement of correctly sizing the respective circuit and fusing it correctly.

 

[dodge68charger]

No Battery Cut-off Switch.

I Dont Have The Charge Wire Going To The Battery, I Have It Going To The Main Starter Lug.

My Alternator Guy Said Going To The Starter Lug And Not The Battery is Fine. Think Its a 6 Gauge Wire.

Thinking Of Putting a Fusible Link Between the Starter and Alternator

 

[pnora]

No Battery Cut-off Switch.

I Dont Have The Charge Wire Going To The Battery, I Have It Going To The Main Starter Lug.

My Alternator Guy Said Going To The Starter Lug And Not The Battery is Fine. Think Its a 6 Gauge Wire.

Thinking Of Putting a Fusible Link Between the Starter and Alternator

Just do it. Painless makes kits and there are re-set able breakers in various amps available. Just google them. They also have convenient terminals. To me the fuse link is old school and outdated.

 

[dodge68charger]

Placing The Order Today. Thank You

 

[RJRENTON]

Bob all newer cars and trucks have the Alternator fused. I cant say when they started but I am sure there was good reasoning behind it. I respect your theory and logic. However I would rather a blown alternator than a wiring mess. I stand by my statement of correctly sizing the respective circuit and fusing it correctly.

Perhaps i should have emphasised the older vehicles and the Mopar alternators. The mechanism of failure was a open diode, due to exceeding the diode's PIV (Peak Inverse Voltage) rating, when/if the alternator was disconnected, inadvertently or intentionally. New diode technology allows for open circuit disconnect capabilities without damage. Yes.....GM and others use a mega fuse in the alternator output circuit. BTW, the alternator on my Escalade is rated at 160 amps......enough to arc weld if necessary.....and has at least 40 different branch circuits, fused by load, and multiple relay controlled devices and circuits. Sorry for the confusion...
BOB RENTON

 

[451Mopar]

No Battery Cut-off Switch.

I Dont Have The Charge Wire Going To The Battery, I Have It Going To The Main Starter Lug.

My Alternator Guy Said Going To The Starter Lug And Not The Battery is Fine. Think Its a 6 Gauge Wire.

Thinking Of Putting a Fusible Link Between the Starter and Alternator

My Coronet is like that, but I am using a bulkhead stud connector at the firewall.
https://www.amazon.com/Fastronix-Pr...ent-Terminal-Connectors&qid=1647623879&sr=8-1

The battery cable from trunk is inside the car and connects to the inside part of the bulkhead connector. Main dash / fuse panel power is also connected to the inner side of the bulkhead connector. On the engine compartment side the starter, alternator, and power distribution box (engine compartment fuses and relays) connect to the engine compartment side of the bulkhead connector stud.
I don't plan to race the convertible, so no external kill switch.
Computer electronics has a separate power feed from the battery.

 

[383man]

Our older 60's and 70's Mopars have the alt output wire on a fuse link. The newer cars use a type of mega fuse. If the alt output wire shorts to ground with the eng off it will burn the fuse link out. When I rewired my alt setup on my 63 with my battery in the trunk I use a 80 amp mega fuse on my alt output wire as its where the output wire hooks to the battery feed on my firewall. Ron