My SB has a rather old heat sending unit that operates a HEAT dummy light. car has never had a problem with over heating. The 2 wires that run from the sending unit are old and one of them broke at the elec. connection to the sending unit. I replaced both elec. conectors after trimming back the wire. On a starting the engine from a cold start the HEAT light came on and stayed lite for 1 minute then went off,,,,,the next morning the same,,,,so I reversed the two wires on the senings unit,,,started the cold engine and it the light did not stay on as the previous 2 mornings. Q.-- does it matter which way the wires are plugged in on the sending unit,,,and did I just have them reversed on the first attempt after making the repair????