So, I managed my first start over the weekend and everything looks great, except the voltage. Battery is showing 12.4 volts on my Autometer gauge and my multi-meter confirms this reading. Once started, the autometer gauge stays the same, it does not increase once the engine is running, however my Multi-meter is telling me that the system is running at 23.9 volts.

I've never seen this before. Any ideas?

Could the gauge be bad? I've never seen an Alternator put out that high of a voltage either... here is the alternator I'm running:

https://www.summitracing.com/parts/sum-810303p