I have a 1992 F150 the temperature gauge is not working. I changed the temp sensor but still nothing. The plug was corroded so I cleaned it still nothing. I had an alt. Gauge but if I disconnect factory wires it sends code and check engine light comes on. Also and don't know if related but the truck is running rich and also has code for egr valve. Running round in circles

 

Welcome to FTE! I'm gonna move this to the correct forum so you may get the assistance that you came here for.

 

Sounds like you were working with the Temp sensor for the computer and not the gauge.
The Temp sensor for the computer has a two wire plug and the Temp sender for the gauge has a one wire push on plug.

 

do the too work separate

 

Yes they work separately.
Each circuit is unknown to the other.