battery is shot, on its way out or alternator isn't putting out. Dead tach is a dead giveaway.

 

alright, after i sanded all my grounds down put new ground wires, seems to be okay, thanks for the help, now i just have to worry bout the knocking sound from pulley area, problem is its not all the time, only when i run it for a LONG tyme and run it a little harder then casual driving. but when it is going its a steady knock. i would think rods would be constant from start up, not sure wut else it could be. but it does sound like its coming more from right inside the timing belt/cam gear/crankshaft cover area. sorry i dont kno all the proper terms.
thanks for the help