AGCO 6690 temp gauge erratic

[stonelake]

Does anyone have an erratic temp. gauge problem on an AGCO 6690? its all over the place even at first start up..

 

[Roadworthy]

Try cleaning your connections and grounds. That may help. On many vehicles the instruments do not run on twelve volts. There may be a lower voltage regulator of five volts or so for instruments. Yours may be erratic. Check your schematic.