alternator question

[redneckaggie]

i have had much alternator trouble as i seem to demand to much from it between the amp pushing 8-900 real watts to the subs, the six door speakers, the leds, cb, brake controller, trailer lights, fuel pump, and whatever else i aint thinkin of at the moment. when i installed all of these alternators i installed a new alternator from napa to run these items as i knew my old one was almost shot. my truck has ate alternators like candy since i installed these items and the new alternator and i have been over every inch of wire in it looking for shorts and there are none to be found. just the other day while installing a new t stat i realized that the alternator i have has a post for the wire to go to the batt and also has a post that says gnd- i would assume this would mean ground as it does on all other electronics i know of. i do not have that post hooked to anything because my dad installed the alternator and said that he had never heard of doing that. so could this be the cause of my trucks taste for alternators.

 

[LCAM-01XA]

Generally that post is for the ground wire of the voltage regulator, but IIRC trucks don't use it. What you really need is a 130amp (or stronger) 3G alternator, can be found in 3.8L Taurus cars but you'll have to swap out pulleys. Adittionally I'd recommend a serpentine belt conversion this will allow you to install a smaller pulley that will speed up the alternator and increase your power output at low engine speeds - factory pulley from a late-'80s Crown Victoria passenger car is what you need for this, it's very small in diameter, tiny compared to the double-V monster that you currently have.

 

[Mat J]

Is that crown vic pulley a double v?

 

[typ4]

No its a serp.

 

[redneckaggie]

ok so is that 130 amp a straight bolt in and plug up or do i have to change, i seem to remember something about a 130 amp that you had to do all kinds of stuff to to get in the truck, is that the same one.

 

[LCAM-01XA]

The large-frame 3G alternator that comes off these Taurii is a direct bolt-in for our alternator brackets. What you'll have to do is swap out the pulleys (Taurus one is a serpentine pulley, you need the double-V for your factory accessories), and also you'll have to remove your voltage regulator from the fender well, and extend the green wire with red stripe all the way to the alternator where you splice it to the wire piece with the same color coding that sticks out the plug you harvested with the alternator (really just cut the harness a few inches away from the alternator and leave all the plugs still in it). There is also a yellow wire coming off that 3G plug, you add ring terminal to that one and bolt it up to the main charging stud. Run your own battery charging wire, I used 1/0 welding cable but that's pretty darn overkill, 4-gauge should be plenty capable of handling the high currents. Don't forget the 175-amp MegaFuse somewhere inline between the charging wire and the battery. It's a pretty simple install altogether, like an hour or so. If you have to reclock the alternator it's a whole another fun experience, I lost the better half of the afternoon trying to do that and I ended up with a ruined alternator, good thing I had a small-frame alternator that I took the guts out of and put them in the large-frame case I emptied.

 

[Mat J]

you will have to reclock that alt. Also the mega fuse people add is seems kinda pointless to me. Unless you put a fuse right next to the battery or start solenoid and a fuse next to the alt. Because if you have a short or get in an accident the fuse will only blow and protect either the battery or the alt. I dont run a fuse on my 1/0 wire. I have shorted this wire for testing purposes and the post melts and falls off the battery and all the wire does it get hot.

 

[LCAM-01XA]

Matt, the purpose of the fuse is actually entirely different - if your alternator shorts out internally (it does happen) it will draw stupid amounts of power through the charge wire as it's directly discharging the batteries, which will cause a very nice fire under your hood. The fuse is there to prevent that, not to protect the battery or the alternator in case the charge wire rubs through - the factory charge wires have pretty thick insulation, and they're also wrapped in plastic loom and also positioned away from any moving or sharp parts, so rub-through is not usually a concern.

 

[Mat J]

thanks for the info. iv had that happen in a car with 1/0 wire and no fuse. The alt shorted internally and burn up all the windings had no fire and didnt even notice any smoke when it happend. A fuse wouldnt hurt at all though.

 

[Agnem]

I put one of those 150 amp resetable circuit breakers in. Seems we always end up throwing another fuse in something just to make sure it blows.