I have a '72 f100 302 motor in my '67 f1. I'll be putting a 200 watt stereo with a 300watt amp. Will I have to upgrade alt. also?

 

Well, you can either add a 2nd battery or upgrade the alt.

 

Well, watts = volts x amps. Volts are nominally 12, and IIRC from rebuilding the wiring harness of my 72 years ago, the stock alternator was 32-40 amps, so 500 watts = 42 amps, so you need a new something. Alternator would be better.

 

2x with Rich. He's spot on with his calculated power and current consumption figures. Add your headlights and you've quickly exceeded the alternator output. You're headlights would probably pulse with every thump of the subwoofer.

3G alternator time!! Do it. It's waaaay easy. Mine cost me a whopping $47 - that's the alternator, megafuse, 4-gauge cables, heat shrink, lugs, etc.

 

what 3g alternator? were did you purchase it? Less than $45 bucks, sounds better than a $100 battery.

 

well i messed up. less than $48 but you get me

 

Yah I dig it... head to a JY and pick up a 3G alternator from a mid-90s T-bird or Mustang (and some F150s) with a 3.8L v-6. Other candidates include Taureses, Sables, Windstars, but it requires hacksawing off a mounting lug. The former do not.

Read this article and it should provide you with all the answers:
https://www.ford-trucks.com/forums/9...g-upgrade.html

Here are a couple of images (by yours truly and Bullitt390) detailing the wiring for a 73-79. Bumpside wiring is similar: https://www.ford-trucks.com/forums/1...tal-draft.html

PM me if you need help... I got pics of it installed in my 70 too.

 

thanks for the help, i really appreciate it. Id be lying if I said it looks easy, but for that price its worth the shot. My buddy has a single wire alt. with the v-belt pully and 100amp output that he would sell me for $75. Do you think that would work in my case?

 

I agree with the calculations and you doing an alternator upgrade, but if your talking about a headunit putting out 200 watts that's highly over rated. I don't think there is any headunit out there putting out that kind of power.

I've done the 3g alternator upgrade. I'm running a Sony headunit, PPI amp for my sub, and 4 Channel Sony amp for mids and highs and it works great. I also run a Sable (Taurus) electric fan without any issues.

 

It **should** work. The things to watch out for is the spacing of the mounting holes and the "stick out" of the pulley - it needs to dimensionally identical to your stocker so the V-belt will line up.

IMO, a JY 130-amp alternator is a better deal... 30 amps more capacity and it's a Ford piece. Plus ya save more than $30 cuz you'll need a megafuse housing, cables, etc... That doesn't come with your pal's alternator, right??

Get your parts from Delcity.net (an FTE sponsor). They've got the housing for $8.54 plus cable, lugs, etc. Or you can shop carefully at your local Autozone or Oreilly's for the lil stuff. I bought an extra long 4-gauge cable, cut it up, and did both my Bump and Dent. The next 3g victim is my 65 Mustang.

 

so with everyone doing the sway, i guess its really not as hard as I think. Buddys doesnt come with anything, but he did have it on a 302

 

If anyone wants a new one.

NEW ALTERNATOR FORD LINCOLN MERCURY 3.8L DB ELECTRICAL | eBay

FORD ALTERNATOR PLUG & 3 WIRE Battery Connector Ford 2G 3G 4G MERCURY LINCOLN | eBay

BUSS 150 AMP HI-AMP AUTO RESET CIRCUIT BREAKER NEW | eBay

 

I know a pick and pull guy/family out were I live so I can get the alt for $20. Since they have serp belts, how do I put my v-belt pulley on it?

 

Easiest way is with an impact wrench. Depending on your pulley, you may find you need to grind down the center of the hub on your V-belt pulley. I had to because the nut wouldn't go on far enough for me to feel safe. Also when you swap the pulleys put the washer that is in front of the pulley on your your old alternator behind the pulley when you put it on the 3g to use it as a spacer.

 

Thanks alot for the extra info. I just want to make sure ive got everything I need. Im going to try and find a Taurus, take alt, battery cable, and megafuse on drivers side of radiator. Than I need to shim the alt. with washers and so forth to put the v-belkt on. That way it doest rub the case. I printed of a wireing diagram from a previous link and will try that one. I also might have to tap it out to a 3/8", no problem there. Sounds good and easy to me!