How many amps and wattage does a 1999 ford explor have on a stock alternator?

I'm trying to add 2 woofers to my explorer (wattage 600RMS) and I want to know how much wattage can a explorer take before the lights start dimming!

It would be nice if it were that cut and dried rolo.
Voltage will be higher. The amp won't be playing 0db sine waves. The user (likely) won't be at full volume constantly. The amp isn't 100% efficient.
The actual average current draw will be a LOT less than 70A -- mainly due to music vs sine waves.

Mark - dimming lights is a side effect of high power audio that can present itself at only a few hundred watts. Actually, most stock electrical systems exhibit SOME degree of light dimming while using some standard accessories -- brake booster, power windows, power seats etc.

600w of amplifier power will likely cause some dimming at high volume, but shouldn't cause a great deal of stress in general for your alternator/battery.
IMO - unless it's severe enough to effect your driving or oncoming traffic I wouldn't worry much about it.

I'm running 1500w rms in a Taurus (130A). Dimming is minor at high volume.

*** 1999 Ford Explorer 4.0L OHV Engine - 130 Amp ***

It's a 130 amp alternator so 12 vdc x 130 amps = 1,560 watts total output on that alternator.

RMS has nothing to due with an alternator the way you stated it, RMS is.707 of the AC peak waveform, it stands for root-mean-square on a sinusoidal wave to calculate what you will get after you run the AC through a full wave bridge rectifier circuit in a DC power supply.

600 watts RMS is approximately 850 watts peak draw @ 12vdc or 71 amps peak draw from the amplifier, thus your answer in a technical nut shell.