[ray_mcavoy]

I think you might have the wrong engine harness.

When you say the temp light comes on, I assume you have a warning light dash cluster, not gauges, correct?

If so, that new harness is meant for a truck with a gauge cluster. That black wire is part of the battery gauge circuit and does connect to the positive battery cable stud on the starter solenoid. But that only works if you have a gauge cluster and the rest of the necessary gauge style wiring.

The correct engine harness for a truck with warning lights will not have that black wire. Instead, it will have a second green wire (usually light green) that goes to the temperature switch (so 2 wires instead of 1 going to the temp switch). Plus, the warning light harness will have a blue wire going to the oil light switch (that wire is absent on the gauge harness).