How to figure out total amp draw?

[loganmossmusic]

So I am looking at some driving lights with 100 watt bulbs in them for my 97 BK. I know that they will draw a total of roughly 16.5 amps, and being that the stock alternator puts out only 85 amps, I want to verify that my car will have enough power to run them. So what do I need to do to figure out the total current draw of my car? Or at least the current draw with the things I actually use running?

[02_Legacy]

you need to put an inductive pickup lead around your positive or negative battery cables, any battery load tester will have this and an autoshop that offers that service should not have a hard time getting you the info you need provided they are nice enough to work with you.

[ctbrighton]

you're not drawing from the alternator, start there.