Coolant Guage Not Reading

[Red79]

Hey, truck in discussion is an 89 D150 with the 5.2. I had the water pump off to replace the gasket, afterwards the temp guage stopped working. I replace the temp sending unit with the proper senor for the guage. I checked the new sensor in hot water and resistance changes, installed without any tape or anything. If I ground the connector with key on, guage will peg, also cleaned inside of connector. I'm stumped?

 

[PaPitt]

I HOPE YOU FIND THIS OUT BECAUSE my HAY Tr. D250 5.2 .. DOESN'T WORK I Bought my truck ..did several parts of maintenance on it .& My temp gauge has never work since I've got it. I too changed the W/P 1st Tune up & belts & hoses & New radiator. Have taken mine to town & had a mechanic attempt to fix my gauge. I finally just added a auxiliary gauge under my dash.
& My Amp gauge didn't work either so later I've added a volt gauge. also.
we changed out my cluster twice It didn't help.