Originally Posted by cheese_man
always check the 6 gauge main feed power wire between the alternator and the batttery
this is most always the problem wire that goes 1st. and check the wire connectors for corrosion
18 years is way too long to rely on that 6 gauge power wire , might as well replace the negative battery wire(s) as well
Good point. I believe this is a fusable link as well, so it could be "open".
Also, while these wires may look good, the copper wire within the sheilding can be green, which drastically creates resistance, dropping the voltage.