Audio Systems: ford explorer 2001 xls, factory speakers, wiring harnesses

Question
first i need to know what my factory stereo and speakers are pushing out (watts).  and i want to know how do i put in my 200 watt stereo i also got a 400 watt sub. I got a 300 watt amp. I want to know should i change the speakers or will it sound good with the factory speakers.  by the way the sub has to speakers and on them they read 400 watts. is the sub a 400 watt sub or since there are two it is a 800 watt sub. the name of the amp is pyramid.  It is 2 channel bridgeable amplification.  the stereo is a sony/  i want to know if i can pull all this together and make it sound good.  Better than the factory sound.  It doesn't have to be the best but it has to have so good thump

Answer
Sounds like you will do fine.

I suggest you have a professional shop do the installation if you are not knowledgeable on how to wire the system.  Based on  your questions it may be easier to have the pro do it.

There are many things you must decide such as impedance matching, speaker size and configuration and bridging the sub amp.  

You are confused about matching power ratings of amplifiers and speakers and how many channels you are going to be running.  

If you do decide to install it by yourself be very careful and make sure you know what all the wires are and where they go.  You can get wiring harnesses at places like crutchfield.com are convenient for the speaker wiring.  

Speaker wattage ratings don't mean much, but amplifier wattage ratings do.  However, the amount of bass response you get (thump, as you called it) is more dependent on the matching of the  subwoofer to its enclosure than any other factor.  I hope you have taken that into account in your design.

Best wishes. Hope it works out perfectly.