You have the wrong sending unit. That is for a light. G is green light for cold & R is red light for hot. Get a sender for a gauge & it should work. The Standard products # is TS-6, but any brand should work. It has 1 term that is flat on top & the connector comes in from the side.

They say money can't buy happiness. It can buy old Chevy trucks though. Same thing.
1972 Chevy c10 Cheyenne Super
In the Gallery Forum