Possibly a tough question...
 

About how many amperes will two 60wrms comp speakers (hooked to a 4x100wrms amp) and one 500wrms subwoofer (hooked to a 1300wrms amp)pull from my electrical system? What if I use two 500wrms subs? Or how would I calculate this? Or maby a website address where I can learn how to figure it out? I do not have many amperes to work with and I am short on cash so the alternator won't be upgraded for a while. Thanx guys.

your speakers dont have anything to do with how many amps will be pulled. its depends on your amplifiers.

I=V/R

at anyrate, your going to dim like a mofo with only a 60 amp alt. just look at the fusing on the amps. should give you an idea how much the amps will pull at full tilt.

You could add up all the fuses on your amps to get total worst (or best, depending on your viewpoint) case current draw.

140 amp's at full tilt....:dunno:

DUDE sooo close! 3x40 and 2x20 so 160amperes total (reading the fuses). My alternator is rated at 85 amperes. How many amperes do you guys think my car will use? I found a place to have my alt rewired but I need to find out the price.

it all depends on whats running...
just the engine alone may need 20-30 amps just for ignition.
another 20 for a/c
another 30-40 or so fo the rear window defrost.
20-30 when you use each window,
5-10 for wiper's,

(these are all generalizations based on what most of my fuses in my car ... honda accord 4 cyl... are.)


just look in your fuse box for things that your car uses all the time... ignition and ac and light's... then go from there...
all the electrical stuff in your car way over powers your alt... my car has a 100 amp alt and total draw at night when its cold and frosty out for me i calculated to be around 150 with all my heaters running and lights and defrost and junk that you think you need but you really dont.... like who needs heat, and the ability to see through window's lol...

The majority of vehicles, especially small cars, were never designed to have a ton of overhead on alternators. Long story short, at full tilt, your gonna dim hardcore more than likely. I'm in the same boat (small car), and if everything goes well when I get some more funds, it'll be a H/O alt for me.

if your are in need of a high amp alternator to slove you lights dimming feel free to contact us and we will be able to work something out for you which fits your needs

Extreme Automotive
Alternators & stater rebuilders
Tel:416 837 5243
Msn: Extreme-Automotive@hotmail.com