what is the thing on the negativ batry terminall there are some wiers on it.

if ther eis wires on the negative terminal you will find they are msot likely either to a solinoide for starting hte vehicle or just directly bolted to the frame as grounds

so you do not no what thay are for do you.if i pull the wiers off the car dies.

thats because the car needs a ground to run its like a battery in your flash light with out a ground the flash light does not work. is there a reason you need to remove the ground wires ?

could be a bad alternator... but I agree whats the reason to take them off..

There are additional ground wires required for a lot of things , especially in a new car. In older cars, the chassis was used to ground all the electronics (no many) and these all returned to the battery via the firewall grounding strap. On newer cars there are a lot more electronics, plus all the plastic and sound deadening that there isn't always an adequate path back to battery. In these cases they run a direct lead back to battery ground.