Today i left my fog lights on at college, class got out and sure enough the blazer did not start (i have done this more times then i can count). I got a jump from a college employee then cruised 26 miles until my first stop sign. I got to the stop sign and the blazer shuttered then dropped down to 400 rpms ran for a little bit then died. I started it back up it reved to 1000 rpms then dipped back to 400 ran for a few then quit again. Once i got it going i got back onto the freeway got off at exit and once again the rpms dropped to a serious low number so i decided to let it run for a bit before i got going again. Why did the RPMs drop that low? Was it because the battery wasnt fully charged?

 

Your battery or alternator is probably suffering from being jumped. I know my car had that problem with a bad alternator.

 

A car battery can only be drained so many times before it's toast...

If you can, try someone elses battery, see if it still does it, or go to an Autozone if you have one, and get the alternator and battery tested.

 

I have a red top optima, it has been drained so many times now. Everything is running good now it hasnt stalled or anything

 

My suggestions are:

1) Re-wire the fog lights so they can ONLY be turned on when the ignition is on. Then you won't leave them on.
2) Use fog lights ONLY when there is actual fog. When there's fog, you'll see them. When there's no fog, all that leaving them on does is cause problems for other drivers.

Check your gauges to see if you show 14V when the Blazer is running. If not, you have a bad alternator. It's also likely that your battery is shot.