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What gauge wire should I use for my alternator?
Most later GM vehicles use a #10 wire for the alternators in the 75 amp range. Car engineers always try to save a penny so they are gambling the alternator will only put out high cirrent for short periods of time. A number 8 wire is more than adequate.
Can you run a wire directly from alternator to battery?
Attach a cable directly from the alternator output post to the positive side of the battery. This allows for full output from the alternator to the battery when heavy electrical demands are placed on the alternator.
Can a battery cable be too big?
A battery cable can be too long, but not too big.
What size battery cable should I use?
As far as standards go, a 6-gauge AWG cable has a 50-amp capacity and is 11.8 feet long. A 4-gauge AWG cable has a 100-amp capacity and is 9.4 feet long. A 2-gauge AWG cable has a 150-amp capacity and is 10 feet long. A 1-gauge AWG cable has a 200-amp capacity and a cable length of 9.4 feet.
What happens if cable size is too big?
Over size cables can in some instances cause problems. In so far as they can reduce the resistance/impedance to such an extent, that the Prospective Fault Current can be higher than the breaking capacity of equipment connected to the circuit. The chances of such being an issue in a domestic installation, are slim.
Are battery cables universal?
Compare the new battery cables to the old battery cables to ensure that both are the same design. Note: If the cables are universal fit, they may need to be trimmed to length and/or have the terminal ends replaced. Make sure the battery cable connection points at the vehicle are free of any rust or corrosion.
Do you need to upgrade the wire for an alternator?
Any time you upgrade your alternator, you should also strongly consider upgrading the gauge (size) of the wire that charges the battery as well as the fusible link in case of a short. The chart below charts the gauge wire required based on alternator amperage output and length of wire.
How big of wire do I need for a 160 amp alternator?
I am trying to figure out the size of wire I need to get for my new, 160 amp, alternator. I found this chart which shows the resistivity/length of different wire gauges. Chances are that I will not be using 160 amps but I want to make sure that my wiring is adequate in case I ever draw a large amount of current.
How is the battery connected to the alternator?
The main battery wire connected to the back of the alternator has power to it at all times, even when the vehicle is shut off. You connect this wire like normal then you run a second wire between the alternator and battery.
How big of a fuse do I need for an alternator?
The fuse is just in case the wire gets pinched or shorted out, the fuse will blow instead of the wire burning up. You should use the largest fuse you can for the wire size, fuses are restrictive to current flow. Typically you want the fuse value to equal 80% of the wires load carrying capacity.