Different alternator for lights? (now with short story)

[race_to_live]

Im in the process of building a light bar that I plan on putting 4 lights on. 2 of the lights are going to be a lower Watt and will usually be on when I drive at night. The other 2 lights will be a high Watt and I will use them only when I need to (more often than not). So my question is do I need to run a better alternator or something like that to help out with running all those lights?

[kimokalihi]

Well how much power are they using?

[93forestpearl]

It depends on what accessories you plan on using while operating the lights. Do you have an aftermarket sound system with an amplifier or two? Do you plan on using the rear defrost and/or AC while using the lights?


Upgrading the wiring from the alternator to the battery helps and so does adding a more significant ground or two.

[Legacy777]

I think I would probably go with a beefier battery before upgrading the alternator. Go with an Optima Yellow top.

[race_to_live]

i might run the defrost sometimes, but as for sound, i have the stock sound system. i dont really listen to sound other then the sound of my car, you know, so you can hear if a part falls off or somethin. and i really dont know how much power the lights will pull.

[vrg3]

Well, figure out how much power the lights will pull. Maybe this will help:

To figure out roughly the amount of current the lights will draw divide the sum of their wattage ratings (in watts) by 12 (because it's 12 volts). That will tell you how many amps they'll use. I'd include all the new lights and also the stock headlights in this calculation.

The stock alternator is rated to provide:
At least 33 amps at 1500 RPM
At least 66 amps at 3000 RPM
At least 80 amps at 6000 RPM

You'll want to have something like 10 amps to drive the ECU and ignition. And something like another 10 to drive the other lights on the car. Then a little more to charge the battery.

If you get a good battery like Josh suggests then you can get away with temporarily drawing too much power because the battery will make up the difference and then will charge up when you're not drawing so much.

So then look at what conditions you'll be driving under and make a judgement call.

[race_to_live]

HOW IRONIC!. So... it is 2am, really tired, and breathing really hard. Not normal for a non party-ier. It all starts with me at my GF's house which is 30min from my house. I ended up falling asleep at her house and woke up at 1:30am. So I hop in my trusty steed and turn the key. WTF I could have swore the motor turned over slow, but I didn't want to start it up again because of how loud it is. So I proceed to drive away. 10 minutes later the lights on the radio would flash when I turn on the defrost...WTF. So after another 5 minutes of driving it hit me, that SOB alternator is going south, and its around 1:45am or so. SOB! So I truned off everything that uses power that I could. I didn't use the brakes much because the lights draw power.

Note: thanks vrg3 for this...

You'll want to have something like 10 amps to drive the ECU and ignition. And something like another 10 to drive the other lights on the car. Then a little more to charge the battery.

I treated it as if I had to make it to the work area after completing a stage lol. Then with only 10 more minutes to go (I still have the driving lights on) the motor wants to die. So it was now time to drive with no lights. Now Im forced to take the back way home. Also, another fun fact, its really cloudy and the moon is nowhere to be found. I live in the county so it was as dark as dark gets. With only 1/4 mile to go (only thing that is on is the motor) the car dies. Yet again WTF. As the car slows down, I hop out and start pushing. I ran my ass off for the remaining 1/8 mile.

Tonight is afriday night, people out drinking and such so cops are everywhere but F it. I wanted to get home. I ran a total of 4 red lights, and 5 stop signs. I think the alternator on the car heard I wanted to get a better one, thus being a complete pain in the ass until I had to get a new one.


NOW the question(s)
What alternator to get?
And what year/models fit?


Last note: If anything in the little story sounds weird, I cant really organize my thoughts right now. Also, the legacy rolls very nice.

[Legacy777]

Are you wanting just a replacement alternator, or high output alternator?

I'd suggest checking these guys out
http://www.maniacelectricmotors.com/

They are where I got my HO alternator from. I am running a WRX style alternator. I switched plugs to the 2-wire plug vs. our 3-wire plug. Maniac does have a 3-wire plug HO alternator for our cars.

Here's their HO alternator selection
http://www.maniacelectricmotors.com/hioual.html

and the normal ones
http://www.maniacelectricmotors.com/29allal133.html

[race_to_live]

So I ended up going with the hella 500's. Just 55W. 4 lights.
Ill post a pic of the light bar sometime here soon

[SPUMONI_RT]

Legacy777 did your replacement HO alt bolt right up with no issues?

[Legacy777]

I got a newer one with the 2-wires vs. our 3-wires. So I had to redo the plug. Other than that it was a direct bolt up. You can get the 3-wire plug alternaters from Maniac, so it should be a direct replacement.