When you have the machine in a specific gear, the wire associated with that gear should be grounded if you check the wire.  Troubleshooting info on the GPS in the factory service manual 

I found those grounding points.  I tested them with an Ohm meter and they all seem good.  I went back to my gear position switch connector to see if I could find a ground in any gear and nothing.  I guess I will have to go back into the rear crank case to see what has happened?  The switch I installed was new in the bag from Japan.

Hi, welcome aboard! I sent my contact information to your message box If you can tell us a little bit more about what you have going on exactly I can more effectively troubleshoot how to help repair it Removing the top cover and taking a few pictures, help a lot as well Does your back light come on? Does any of your LEDs work at all? Does the screen look discolored? Possibly have water damage internally? These few things will help narrow it down -AKATV    

Hey I could use some help AKATV with 03 Honda Forman 450 screen/meter repair. Thanks in advance 

Hard to tell without seeing things.  You should have a ground wire from frame to back of engine, and another from starter bolt to battery negative.  # 8 and 9 here   https://www.partzilla.com/catalog/honda/atv/2000/trx450es-a-fourtrax-forman-es/battery   You have an N showing on the meter and a strong green light on the N indicator on the meter?