Just posted this on another thread a couple minutes ago....
This is from memory, so if I'm not right on all the wires, sorry.
There is a relay on the Aframe just in front of the steering post. Make sure there is power getting to it (red wire I think or red/white). There should also be a red or red/white wire leaving the relay. With the sled running, check to see if it is getting power across the relay. There should be a diagram on the relay that makes it obvious which wire I am talking about when circuit closes. The wire leaving relay powers gauge and some other accessories.
You can 'jump' the connector to check if your gauge lights up and then order the right relay. The dork at the auto parts store sold me the wrong one when I brought mine in. Had the same problem on my 2011. Good luck.