Hi Dan, not sure if this is related, but I thought I'd post the info in case somebody finds your thread via search.
Eventually the Livorsi GPS Speedo will run through it's self check, settle on Zero, then rise to the 9 - o'clock position and freeze. This indicates there's no communication between the gauge, and the antenna. Check your wiring and connections first, but if the unit is a couple years old, it could be a dead battery found in the antenna.
The antenna was originally designed to be installed independent of any power source, and primarily deployed as a tracking device by
this company. So they designed it with a flat coin type battery. It's not designated as a "user serviceable" item.

I took mine apart and see why, it's a little tricky.
The battery inside the unit is a CR1632, found almost anywhere (usually under $2 online via eBay, etc.). It has a very limited useful life, and is NOT rechargeable.
The easiest and permanent fix is to connect your GPS NMEA output wire to the "S" terminal on the back of the gauge. This allows the gauge to display the speed as tracked by your GPS. The "S" terminal is where the orange wire is connected from the hockey puck antenna.
It's very important you remember to use your GPS configuration and setup screen to turn on NMEA output. Most default to "off" out of the box. In the "On" setting, NMEA data (which includes your speed) is sent to the gauge.
If you're handy with a soldering gun and want to replace the battery, go for it, but remember it will eventually die again. Livorsi will replace the battery for you, but at the time I called, it was around $75 plus shipping fees.