Originally Posted by carringb
They are separate circuits, so if you're seeing low voltage on both (and not other ignition switched circuits), you probably have a corroded dash ground somewhere.
What are you trying to power through those outlets or are you simply concerned at the current readings? Are any connected devices blowing the existing or previous fuses?
When checking voltage at those outlets be sure to check your starting/chassis battery concurrently and compared--they should be equal.
As CarringB says this could be nothing more than one or two bad grounds which could be corrected by running those to a solid point under the dash.