Electric Fan Question

  • Sponsors (?)


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!

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.

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

3/4 “ Black heat shrink tubing, 4ft length, $3.39
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=082-058

3/4 “ Red heat shrink tubing, 4ft length, $3.39
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=082-064

Pre-fab 4 gauge cables with lugs already on the ends are available in most auto parts stores. Look for the starter switch to starter cables.

My 3G alternator swap:
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.
 
Georgie said:
what kind of alternator should i get?? 3G, 130 amp, 150 , 200???????????????????? and what should they cost and where would YOU get one?
What alternator do you have now?

A 160 amper would work well, or a trusted 200 amper (some of the ones I've seen are a little hinky). The last thing you want is to not have enough juice with all your stereo stuff and a fan; better to pay a little extra for more output the first time.

Good luck.
 
just make sure the hi output alternator makes adequate amperage at idle rpm. I bought a 180 amp alt for my s-10 that performed worse at low rpm than my stock 100 amp one.
 
$140-$350

Depends where you buy it and what amperage. A 140-180 amp alt should do you just fine. like stated just make sure it is charging at idle, my 3g wasn't so i had to put the 2g pulley on it and now it charges all the time. Personally I bought mine from autozone because of the lifetime warranty and the price, i used a 2g from a truck for the core charge so it was only like $100 for the 3g.

Follow Jrichker's 3G install guide and you will be good to go.

Level of difficulty= Amatuer/shade tree mechanic
 
I picked up my 130A 3G off of ebay from midwestmustangs for $31.00 It even comes with a section of the wire harness to make the swap super simple. I didn't need anymore than 130 amps since I can't hear the radio in my car anyways

Hardest part was getting the die grinder in the right spot to grind away at the bracket for clearance.