I just installed 4 150 watt KC Daylighter on my roof. Currently I do not have any other major sources that draw from the alternator. Does anyone think this is too much for the alternator to handle? I don't use the lights much but when I will be using them it will be constant when offroading. I could always ebay them and buy smaller watt lights, i just figured i'd go with the highest output because it would be cooler. Thanks for the input...

You will be pulling about 45 amps with those 4 lights, that’s about 1/2 of the alts output. With headlights and 55 watt fogs on you got 58 amps, if your fogs are like the 2000 stock ones I think they are 35 wats so thats 55 amps. I think you would be fine if you make sure all other accessories are off. Maybe put in 2 switches so you can turn on the outer 2 and the inner 2 separately.

If you draw more current than your alternator will put out, you'll just deplete your battery

I only use my roof lights sparingly, there are 2 150's and 2 100's up there. (along with 4 more 55 watt lights)

Make sure you run a heavy enough wire (I used #10 for each pair) so you minimize voltage drop. Voltage drop can cause you to draw even more current.