Nikon d70 white balance?

In full auto mode why are my photos so dark, the levels are all in the black and the white side always has to be adjusted?

If your images are consistently underexposed, you will need to look at your EV adjustment and make sure it is set to -0-.

Auto white balance is something I never use.

In fact not only do I set my cameras white balance to manual and match the ambient light to the white balance on the camera, but I also shoot RAW and include a shot of an Xrite Colorchecker Passport in the first shot under each lighting condition.

Here is how that works

http://www.xritephoto.com/ph_learning.aspx?action=webinarsarchive&eventid=803&eventdateid=4460

White balance will not affect exposure (how dark or light the image is).It sounds like you're shooting with basically not enough light. Increase the ISO or add flash.