temp gauge on a 2005 uplander

guys..im a ford tech and i have a 2005 uplander that has the temp gauge not reading.It also has the cooling fans that run all the time..had this problem last summer and i changed the temp sender in the head beside the thermistateand it correctied this problem..i changed it again and this time it still not correcting this problem.

anyone know if there is a secondary temp sender or what i should look at next. hard to pin point since all we have is ford tool at work lol

thanks