Need help finding a ground.

I am looking for the ground that goes to the turnsignals, and dash gauges. I'm pretty sure I have a high resistance somewhere that is causing all my gauges to not read correctly, and my turnsignals are dim and slow?

If anyone knows much about this it would be a great help.

Dim and slow turn signals eh? Sure you are gettin a healthy 13v when running? Try checking the main battery to chassis ground while your checking the voltage.

Thats why I think I have a bad ground because when I check the voltage across the battery while the engine is running it reads 13.5 volts. But the gauge usually reads somewhere between 9 and 11 volts. All my gauges show small discrepencies like this.

I'm running a deep cycle optima and a 100 amp alternator, both are only 2-3 months old. I have already replaced both pos. and neg. battery cables. I've read that people have added a cable from the alt. case to battery neg. and replaced the ground strap that goes from the head to the firewall to improve things. But I'm wondering if those changes will help my specific problem.

I'm hoping 5-90 will chime in because I know he has experience dealing with the power and ground distribution on the XJ.