Fans...Electric or Belt spun???

The 3G or any alternator including the stocker becomes harder to turn only as you put more electrical load on it.

If you have the stock 65A alternator, a decent sized electric cooling fan(s) is going to tax it. Check out Pa-Performance -- they offer 95A and 130A upgrades, high quality stuff, all new. Don't forget to upgrade the alternator wiring with the more powerful altnerator. www.pa-performance.com

I can get a 3G out of a wrecked 01 V6 for cheap at my mechanic's JY.

I have an 83' Mustang and just installed a Perma Cool electric fan and it seems to work great. My only problem is I haven't had a nice hot day yet to see if it keeps my engine cooler. Some of the requirements for an electric fan is that on a 302 you need a minimum of 3000 cfm and a fan that covers 70% of your radiator. I got the 16 inch fan from Jeg's for 88 bucks, it's got aluminum blades and only pulls 9 amps if i remember right. There are a couple different temp controllers to choose from also. I got the 60 dollar one but there are cheaper ones. It's got an adjustable thermostat and the sensor is threaded. I just drilled and tapped into that boss on the water neck and it looks factory. If you can't find a half inch tap, you can buy a new waterneck from Auto Zone with it already done for 12 bucks.

P.S. You don't need a fan shroud with it either. Look em up at www.perma-cool.com

astronut1885 said:

Yeah. His main point was that the 3G alternator was harder to turn than the stocker, and would put more load on the motor. I didn't agree, but I never really looked into it. Also, my car will stay one notch below the top red mark on my stock gauge without any accessories on, will drop to 1/2 with either the heat or lights on, and will go to about 1/4 power with lights and heat, and the blinkers slow down. Do you think I'd need an alt upgrade to go with an elec. fan? I think I would.

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that is a little weird. sounds like your gauge is bad or you have a short or something that is drainin the battery overnight, etc. as Michael said, it only puts out what is needed. and if it is putting out a lot with no accessories, to me that suggests that your battery is drained.

sounds like you are already taxing the system with lights, etc on. i bet that another draw might really present tractability problems. youre already below what you should be (12.6 volts is breaking even, right?). i would upgrade for any fan with the way it sounds
BTW, you are a little worse off than me [with headlights, brights, fogs on], but not by much. it goes up when off idle, right? BTW, its hard to compare idle voltage since the stock gauge is too inaccurate for that and everyone has idle set differently. mine is at ~650, and the output jumps even when increasing to around 1K.

Hissin is right, I'd be checking the battery. If you put in a new alterntor on a bad battery, you take the chance of blowing the diodes. Make sure the battery is fully charged before you install the alt, as alternators weren't designed to charge a depleted battery, but to keep a fully charged battery topped off.

If you run a giant stereo, fan, ignition, lights ,fogs, etc., your stock aternator can't keep up with the draw on the battery. It's working at all times to keep the battery charged, and it can't keep up with the battery depletion. You start the car in the morning and your alternator is huffing and puffing trying to charge the already low battery. Diodes don't like that, and pretty soon they just give out. You'll know some morning when you go to start the car and the battery is completely dead, even though it was fine last night. When the diode goes, it usually starts a reverse flow of current from the battery, with everything off. The higher amp alternator is a very good investment.

3000 cfm???!!!!!!! wow, I bought one that is like 1700 cfm and 17" for my windsor, looks like I'll need an upgrade.