Here's one for the gurus!
I am curious how much the stock alternator in my '93 4x4 will put out (watts). There will be some needed amount to operate the vehicle, of course, but I am wondering how much I have left over to play with for offroad lights or what have you....if I go shopping to get some, I'd like to know what power range I should be in (55W, 100W, etc etc).

Somebody on here knows! So far, the vehicle is stock. I'll probably also put in a CB, but that's about it.
Thanks!!

 

Alts are rated in amps. In order to figure out the amperage draw on the lights you take the wattage and divide by voltage 12volt in the case of a regular car. Thus if your running two 100w bulbs.

200w / 12v = 16.7 amp.

 

Hi XXX, thanks....I do understand Ohm's Law, E=I/R, and P=I^2R, etc.....what I need to know is how much power the stock alternator is capable of putting out (its "ampacity", really, or power factor, or something).

Like, how many amps is the thing usually outputting on a stock vehicle, and then, what is it CAPABLE of putting out, so I don't kill it with accessories.

If you exceed that rating, you will then probably start to see less and less voltage at the battery terminals, where you need it. The 14.something volts becomes 13, 12, 11 etc etc the more current you draw. This also causes devices to draw more current, in a thermal runaway condition (it's why you kill your skilsaw if you use too much extension cord).

Sorry if this is a doofus question, I just really want to know and don't know where to get that spec.....

 

I think it's 60 or 80 amps. Memory is a little fuzzy right now.

 

60 amp in the 93's. Both 3vz and 22re. 70 amp I believe in the 93 4runners. Without a vin I can't be sure.

 

Thanks, XXXtreme! That's what I needed.....just found a post about how to measure the draw of the ignition....they assumed roughly 6A for that. Then tally up the accessory use, and you can find your overhead.

Eventually I'll upgrade the alt anyway, but for this winter, I just want some extra lights on the front bumper (gets mighty snowy in these parts!)....