Temp gauge inoperable

[JimE]

Hello fellow FORD Expedition owners and everyone who's had the pleasure of repairing one. I have a 98 with the 5.4 and my temp gauge recently stopped working. I was able to ground out the harness which in turn shot to hot on the gauge. So I changed out the top sending unit and no change. Does the other sending unit located under the intake have anything to do with gauge? The darn thing wants to run one day sorta alright and then not worth a shit the next(Acts like it's loading up, no power) have not noticed any black smoke. Of course just real rich smell coming from exhaust. I recently changed injectors, plugs and coil packs before I realized temp gauge not working. Thank you for your time and ideas

 

[Hamfisted]

Yeah that one under the intake manifold runs the temp gauge.

 

[JimE]

Grounded the bottom harness and no change in the gauge unlike the top harness which immediately went to hot when I ground it. So both run the temp gauge?

 

[JimE]

Alright well I'll start looking for a short in the wiring thanks for the help.