Doing my latest oil change, I noticed the ground cable going from the engine block to the frame is in pretty rough shape, especially at the frame contact point, and I've had voltage issues for almost a year now. Car runs usually around 14.8-15 volts no matter what is running.
Question is,
A. Can I get just a replacement cable from somewhere without having to measure and cut my own, crimp on ends, etc. If not, any idea what the length/gauge is for a 2004 L36 cable?
B. Would having a bad ground cable cause the high voltage issue I'm seeing? The info center reads 14.8-15 (sometimes as high as 15.2) and readings are confirmed with my DVOM, and the dash is spot on, voltage wise. Everything seems to be working ok, but the unusually high voltage has me concerned.

Seriously? No one knows the gauge and length of the ground cable from the block to the frame? I'd like to get this done before I'm digging through 2 feet of snow to lie under the car and replace it...
Id rather just use an off the shelf replacement, so if I can go into an Advance Auto and just find what I need, already crimped and the right gauge/length that would be great. Stupid cable is all green and white. Looks like mold. Especially where it contacts the unibody up by the front fuse block.

That'* a very good question. The battery cable design seems to have changed in 2000, so I can't be of much help. For what it'* worth, RockAuto lists two negative cables for you, so you just need to see if it'* the short one or the long one:

ACDELCO Part # 2SX171A **#15321264, 88953169}
CABLE,BAT NEG 431.8MM LG

ACDELCO Part # 2EG32 **#15321235}
CABLE,BAT NEG 812.8MM LG

Good luck!