Big Posi and Neg wire from Starter to Battery and Alt wires..........

[from6to8]

I was thinking of possibly changing the big power and ground wire from the starter to battery but realized that there's more in the harness that if you were going to go new, might also need to be changed. I think mine is fine but I'm just eliminating some possibilities so thinking of some things. Did any of you change just the big power and ground and not any of the other harness and doesn't the Alternator wires come off that harness as well in case you wanted to change it? What did you guys end up doing?

I don't think there's a lot of traffic on the boards much anymore aside from the same guys who usually help out. I didn't necessarily want to post in my build thread in case others might not even look at my thread but might see this and have an opinion. I usually tag @Noobz347 @AeroCoupe @gkomo

 

[AeroCoupe]

If you replace the power wire from the alternator to the battery do it with a 4 ga and a 125A wafer fuse. The run a 4 ga wire from the negative terminal to a solid connection of the front subframe. Run an additional 4 ga wire from the some location on the subframe over to the block of the motor. This is generally referred to as "The Big 3".

If the battery is in the trunk of the car then run a 1/0 from the alternator to the battery and again I would run a 200A wafer fuse. 1/0 cable is good to 200A and the end rush from the starter smoked a 125A fuse on my car. I would also run a 1/0 ground from the battery to good ground location in the trunk and bolt that connection. You will still need to run a 4 ga ground from the block of the motor to the subframe and a 4ga from the starter to the alternator. This is similiar to what I did on my Thunderbird as the battery is in the trunk and voltage drop tests confirmed everything was working as it should. I say similar as your car will not have the starter solenoid on the inner fender like my Foxes do so I ran the battery wire to that and the starter wire to it as well.

This is documented on here quite a bit with some nuances but in general all done the same to achieve the same effect which is steadier voltage and less voltage drop on the wires in high demand situations. Some will say its overkill but they are not feeding 1000+ watts of Fogate and Soundstream amps, electric fans, ignitions, fuel pumps, etc. If your car is basically stock then I agree that this is not a wise expense.

I would say that if the charging wires are factory you may want to do a voltage drop test and see if they need to be replaced as the factory wiring, alternator, and battery were sized properly but they did not put anything more into it than they needed to cut costs.