im looking to get a new 130amp alternator for my stang, well i was wondering if it would hurt the electrical system if i go bigger? i see 150 amp and 200 amp alternators, well wouldnt they do more damage then good, just wondering here, whats a good choice?
It would not hurt your electrical system to have a bigger amp alternator, but unless you really need all that extra power then you are just wasting your money. A stock replacement 130 AMP alternator for a 94-95 Mustang is an easy upgrade and is usually plenty of power for what most daily driver cars require. Unless you have a large stereo system or something then 130 should be fine.
Use these sites for information on the right way to do the wiring. Some people will tell you that you can skip the wiring upgrade, but it will catch up with you sooner or later. A fire in the wiring harness is ugly and expensive.
Under no circumstances connect the two 10 gauge black/white wires to the 3G alternator. If the fuse blows in the 4 gauge wire, the two 10 gauge wires will be overloaded to the point of catching fire and burning up the wiring harness.
Electric fan = 3G alternator if you want long life & reliability from your car.
Figure this:
Ignition system & computer = 12 amps
Fuel pump = 12 amps
Exterior lights = 15 amps
Fan (heater or A/C) = 15 amps (can run between 5-25 amps depending on setting)
Radio & instruments = 10 amps
Wipers = 10 amps
That's grand total of 74 amps from a 65 amp alternator. Talk about overdrawn at the bank!
ok, im going to got with a new 150amp alternator i found for $124, now what i need is a basic wiring diagram from someone plz, cuz im putting my battery in the back and im corn fused about how to wire it. thanx guyz
jrichker put what links you need in his post. The 4 Gauge wire can be bought anywhere that sells that kind of thing. Welder supply stores and stereo shops both have the wire you need. Install is easy, just take the big rectangular harness that doesn't hook up to the 3G and tuck it away, plug up the D shaped harness into the new alt, cut the stator (white) wire from that harness and loop it back to the stator plug (single wire harness) grind the stock alt bracket to clear larger alternator, -4 gauge wire to the starter solonoid, bolt up and your none.
A single 4 gauge wire from the battery in the trunk probably isn't going to be big enough. You're likely to have starting issues with that. The longer the run of cable, the bigger the size must be to overcome the resistance in the extra length. I run a double 2-gauge cable (soldered together both cables in a jumper cable set). Many people run a 1/0 welding cable. Just a heads up. If you run out of room for big cable lugs on the fender-mounted starter switch, you can also run either the battery hot or the alternator output to the hot side of the battery.
Lastly, if the car's not overloading the twin 10 gauge wires now, it's unlikely to with the simple addition of a larger alternator. Alternators don't simply 'put out' the extra current they have the capacity for. The current is drawn from them by the accessories. So whether you have a 65A alternator, or a 150A alternator, if the accessories/electrical needs total 40A, that's all the alternator puts out.