i just did the big 3 on my car and the question is the power coming from the alternator to the battery do i need to put a fuse there or not? i left the stock wire intact from the alt to the bat because if i cut it i wouldn't be able to see if my alt is failing or not since it wouldn't be going through the fuse box!!

now if i put a big fuse between the wire and still have the other stock fuse in the fuse box there will it mess up anything? or should i just leave it like it is?

i dont run fuses from the battery to the alt, but some do. i guess its just another safety measure some people decide to take.

but no not needed.

I would just remove the stock wire and replace it with the larger wire and not use a second wire from the alt to the battery.

Edited March 24, 200916 yr by nmssd12

it s a good safety measure but u deffinetly do not need it it would be kinda waste

Here is what is going on here -

If you do not put a fuse on it-

It is common practice not to as is the norm.

You will have less resistance going directly to battery.

If the fuse pops and the stock wire is still intact... it may either catch the factory wire on fire or will pop the internal fuse and fry the voltage regulator by spiking the voltage!

If the fuse pops and the stock wire is not there, it will fry the voltage regulator due to voltage spike.

If you do put the fuse on there-

Excessive current will not be possible( this is VERY VERY unlikely because an alt can only produce so much current after heat loss)

If the fuse pops(due to a short), it wont damage the battery.

PLEASE NOTE - if you can't connect a wire going from the alt to the battery without worrying about a short... you shouldnt be installing the wire,

Not putting a fuse on there outweighs putting one on there.

That's why most dont.

i dont run fuses from the battery to the alt, but some do. i guess its just another safety measure some people decide to take.

but no not needed.

thanks man that's all i need to know!

Here is what is going on here -

If you do not put a fuse on it-

It is common practice not to as is the norm.

You will have less resistance going directly to battery.

If the fuse pops and the stock wire is still intact... it may either catch the factory wire on fire or will pop the internal fuse and fry the voltage regulator by spiking the voltage!

If the fuse pops and the stock wire is not there, it will fry the voltage regulator due to voltage spike.

If you do put the fuse on there-

Excessive current will not be possible( this is VERY VERY unlikely because an alt can only produce so much current after heat loss)

If the fuse pops(due to a short), it wont damage the battery.

PLEASE NOTE - if you can't connect a wire going from the alt to the battery without worrying about a short... you shouldnt be installing the wire,

Not putting a fuse on there outweighs putting one on there.

That's why most dont.

makes sence but i was just concerned about running two different sized fuses (stock, then the 300 amp)..but thanks for the help!

Well just remember that the fuse is there to protect the individual wire that it's on. So it doesn't matter if they are two different size fuses because the two wires are different size. Also, you should keep your stock wire there and just add the second one.