Alternator Questions with my 93

one million and one.

From a safety standpoint, then yes you should rewire the circuit correctly. Which wont cost $30 and 1 hour of your time.

To speak practically and real world, if you dont add any more electrical drain to your car (big stereo, more lights, electric fan), then the electrical system wont draw enough current to burn up the wires.

I recommend to upgrade the wiring.

yep. The fact that it sounds like you are discharging the system with current equipment suggests that if you installed more alternator, you would burn wires (instead of simply being in a state of discharge).

The factory 10 gauge wiring is horrendous. The upgrade is easy, so I would do it. If wiring is not your thing, PA-P sells a kit which is premade AFAIK (I have not used the kit).

Then you can run a ton of alternator and not worry.

Good luck.

pa-performance has a direct 130 amp replacement for your 2G. No muss, no fuss. I would STILL upgrade the power wire. If you know that your alternator is in good condition but is still unable to keep up then your problem may be wiring anyway. My suggestion would be to keep your current alternator and upgrade your power and ground wires to see if that makes a difference before dropping a wad of cash on an alternator that you may not need.

Dagger and Hisson both have good points about the wiring. I assume that you meant at idle or low engine speeds where the factory alternator is the weakest.

I was given this tutorial in another thread. This is what I am going to do cause I am in the same boat as you, but the drain isnt that bad. Just lights dim and stuff at idle when my sterio is on.

http://wcfords.com/articles/tech/alternator/alternator.html

66mustang93 said:

I was showing a friend mine I had lunch with yesterday. While driving steady about 40 with the AC on, I cut off the AC and the voltage meter jumped up over one notch on the gauge. That is not normal is it? I expect it to move slightly but not that much.

Click to expand...

Need more info. On the surface I will say this is normal, but this might not be so. Having the A/C clutch engaged does not require that much power. Nor does the lowest blower speed. If you have the HVAC blower motor running on high or the second to last setting but with other accessories on, it can put a dip in the voltmeter. The blower motor is a relatively large draw, as far as accessories go.
You did not note info about the blower motor, nor what other accessories were on at the time.
Good luck

Don't be afraid of the re-wire, it is almost Murphy proof if you can read and aren't color blind.

I am very careful to maintain backwards compatibility, so I did things a little different. The white/black stator wire gets the insulation stripped back about 1 1/2" in the middle of the wire & cut in the middle of the stripped area. Then a short length of white wire with a 1/4" slip on female spade connector gets spliced on to the white/black wire. Slide on enough 1/4" heat shrink tubing on the white wire to cover the solder splice you are going to make. Next all 3 wires get soldered together & the heat shrink tubing gets shrunk. When you finish, the white/black wire looks like a "Y" with 1 white arm and 1 white/black arm. I left the black/orange wires connected to the original plug and did not do anything to them. When you are done, the original plug still has all the wires connected to it and they are still functional. The extra white pigtail wire that you spliced, soldered in & covered with heat shrink tubing is just long enough to plug into the 3G without much left over.

I ran the 4 gauge wire under the front of the engine next to the 4 gauge wire for the starter power feed.
It came up the same path as the fuel injector supply lines, and gets bolted to the power output lug of the 3G alternator. The 125 amp fuse is mounted on a plastic panel bolted to the stock ignition coil mounts. One of side of the fuse has a 4 gauge wire connected to the battery side of the starter solenoid & the other to the 4 gauge power feed wire for the alternator.

I had some 1" silicone aircraft heat shield tubing that I fed the 4 gauge alternator power feed wire through and tie wrapped & clamped it in place with some aircraft cushion clamps. That provided the wire extra protection from road debris and rocks. Some heater hose could be used to do the same thing.

Apart from the grinding I did on the mount bracket, there wasn't much to it. Rather than just grind a notch, I ground the whole web back to the thick part of the bracket. It looks much more factory that way.

Here's websites with pictures of the 3G installation...

See http://www.geocities.com/smithmonte/Auto/3G_130A_Alternator_Upgrade.htm - all the tech data you could ever want to know
OR
http://www.mustangcentral.net/tech/alternator.html - excellent pictures of installation

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.

The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.

Electric fan = 3G alternator if you want long life & reliability from your car.
The electric fan saves some HP. The stock fan's parasitic drag runs from 7-12 HP depending on who you talk to. The electric fan uses about 1/2 HP of power from the electrical system.

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!

See WWW.partsexpress.com for the fuse & fuse holder.
Fuse @ $3.90 each (need one) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=071-952

Fuseholder @ $5.80 each (need one) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=263-630

4 gauge black wire @ $1.25 a foot (use string to lay out routing & determine length) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=100-196

4 gauge red wire @ $1.25 a foot (use string to lay out routing & determine length) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=100-194

4 gauge ring crimp terminals (package of 5) $3.25. http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=095-584