Got a 89 lx that has a 92 5.0 motor in it, every since i bought it it would surge at idle and the volt gauge would always stay at 10 volts.Its been starting slow so i thought it was the battery and replaced it with optima red top. Still starts slow so replaced starter switch on drivers side fender, still turns over slow. So i think it is the starter that i just replaced a few months ago. But heres the problem that has stumped me, i have been trying to get it to quite surging for a while now, and found out that if i crank the car up and let it idle, it would surge, but if i take the positve battery cable off the surging quites and the volt gauge jumps to about 13 volts and the volt light comes on.as soon as i touch the postive wire to the battery againg volts drop and surging starts again. I took my battery tester with load switch and left the car running with battery cable unhooked.put ground from battery tester to battery and positive battery tester lead to positive lead on car and when i hit the load switch the car cut off. Do you think the alternator is bad?