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high amp alternators


fordboi415

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I have a high output stereo, 3 6" 130 watt lights and an air horn powered by a 1/4 horse compressor, my question is how long does my stock alternator have before it dies?
 


Wicked_Sludge

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your barely even taxing the factory alternator with your setup.

your lights are 390 watts total. your horns are 190ish. lets say the average aftermarket "big" stereo draws 500 watts RMS. thats just over 1,000 watts or just 77 amps @ 14 volts. your factory alternator is 95 amps, leaving 252 watts for everything else (that is, if you were to drive around town with the stereo cranked, lights on, and horn blaring...which i doubt you do alot).

if itd make you feel better, you can swap in a 130 amp alternator from anexploder, but it isnt necissary.
 

Randy960

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Another possibility if you need something bigger than 130amp, you could probably get an alt from something like a superduty. Ford almost always uses the same bolt pattern and wiring plugs, you might just have to swap pulleys and maybe even trim the bracket a bit.
 

mjonesjr

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You could also have a stock 130A alternator.
 

mjonesjr

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are any modifications needed to put a 130 from an exploder in
Make sure you don't have a 130A stock alternator first.

If you don't have a 130A alternator, the Explorer 130A unit is a plug and play unit.
 

mjonesjr

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i have the 95 amp internal fan internally regulated alternator that came stock on my 3.0, i figure all i will need to change is the power cable to the battery from the alt (4 gauge min) and maybe add another few ground straps?

hows that sound?
You can't just bolt in the Explorer 130A alternator. The mounting is different I do believe.

4AWG is over kill for a 130A alternator. I would use 8AWG and then also do the "Big 3" modification. Do a search and you will see what it is.
 

4x4fun

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first the part that goes wrong in a alternator is the diode trio its this lil part inside that makes AC/DC its like 8 bucks. i had to learn how to rebuild them in the service. that's what is replaced by a Mexican* some were when you by one thats rebuild. it takes about a half hour to replace. an new 130amp alter is about $180 for a rebuilt one divided by 8 is 22.5 so if you went thur one ever year which is very unlikely you could rebuid it for over 22 years. befor it becomes cost effective i have two years on my stock 95 amp alt. with 400 watts of lights up front and 1000rms watts of stero and im working on 2 years with my 06 so for my math, that truck would be a classic before it would be worth it to get an 130 amp

just something to think about

having said that im prolly gonna get a mean green one here soon just becasue i can and its bragin right :icon_hornsup:

and 4 gauge wire is kinda over kill i think.

* i have nothing against mexicans
 

MAKG

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Rectifiers blow up, but they are by no means the only way these things die.

For instance, dead bearings and broken brushes come to mind.

And more than a few "bad alternators" are really bad wiring.
 

dennis461

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If you decide to get a bigger alternator,
--------------------------------------------------------------------------------

www.motorcityreman.com they get my vote.
Bought a used 200 amp alt, one from TRS classified
, which broke after over a year.
Sent it back and got a new one free !!!
 

4x4fun

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For instance, dead bearings and broken brushes come to mind.
im not a pro by any means ill give you brushes but iv never heard of a bearing going under normal driving, if your a mudder or something sure. but idk

and bad wiring is cheep parts.

not trying to start a fight

everyone has there own path in life
 

Wicked_Sludge

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im not a pro by any means ill give you brushes but iv never heard of a bearing going under normal driving,
ill send you mine when i finally get around to replacing it. the front case bearing has been shot for 2 years now...i have to spray it with penitrating oil every few weeks to keep it from grinding and squeeking. its only a matter of time before it fails catastrophically.

ive seen bearings seize up and smoke belts, or allow the armature to contact the field windings...that sure makes a mess.
 

Chris.S.

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So how do I tell what Alt I have? Is there a tag or pn on the Alt. itself?

I'll go look and see.

I've added 400 watts of light, a windows mounted gps, a cb and I have a 360watt amp on the way. I think I'll be fine on the stock, but..........
 

Will

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An alternator is like an engine--you need to see the power curve before you are sure of what you are getting. I put a 100amp kit on a 40amp alternator (long time ago) and it probably put out more amps, but not where I wanted them. It put out less amps around idle and made it worse. Any factory alternator upgrade I would do without hesitation. I would not buy an aftermarket 200amp alternator that was in a factory frame.

Optimas are great batteries. With a diesel a set of regular plate batteries lasted me about 2 seasons--and in the middle of the second winter it was on the charger for an hour before I needed to start it. I've had this pair of red tops for 4 winters and it starts just like new. It's a huge difference in how long you can crank them without killing it and if you do need to hit it with the charger (like when it's below 0) they soak up the current much faster and on the three nights it did go below zero 5 minutes with a 15-amp charger on the pair was enough to warm them up enough. When you have 21.5 compression on a 379cid V8, with glow plugs also competing for the current, you get to know batteries.

Before I bother to ever upgrade an alternator again I would put an ammeter on what I have and see what my actual need was. The battery easily deals with large intermittent loads and the alternators job is to catch it back up. Almost nobody needs more than the factory alternator. But if you find you need one, make sure you see the curves and know for sure it will actually give you the extra 50amps you need while idling around the cornfield spotlighting deer or powering the 150amp draw from your sound system at the post-prom kegger.
 

LittleHorse

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Your personal vehicle modifications are obviously not subject to the National Electric Code, but...

according to NEC regulations on Allow Ampacities of Single Insulated Conductors rated 0-2000V in Free air, a current of 130A requires a 4 gauge wire with 90°C insulation (it's good up to 140A). For 60° insulation you'd need 2 AWG and 75° insulation would require 3. The insulation class is usually printed on the insulation.

Not saying your wire is going to melt the second you turn your lights on, and there are obviously more than a few that have used 8 AWG, but if the NEC considers it unsafe to use any less in a house or other building, then it's probably for a good reason.
 

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