I tried jumping it twice w/ two diffrent wires and cars. mylight dont dim. the horn works and lights and air. i dont think radio works. maybe a fuse is out i dont knowi wont be able to do nothing till the third but in the meantimne i need to know what im lookin for. it does not crank but the key springs back.

If you have access to a voltmeter, put it on the remote battery posts and see what your voltage is. Have someone turn the key to the start position and read the readings on the meter. If it's lower than 10.6, you have a bad battery. But if it's higher than that, your battery is fine and your problem lies in either the starter solenoid or you could have a blown starter fuse.