Two important concepts that have not been addressed are voltage drop is due to current flow and resistance can sometimes be due to the heat that current flow caused when flowing through a high resistance spot. You cannot measure voltage drop with an open circuit or the circuit turned off. Open and off circuits ALWAYS show battery voltage. There has to be current flowing and the more current the larger the drop. That current can heat up the corroded connection and raise its resistance even higher.... maddening finding these as they "look" ok and test out as low resistance and even work ok for a while till the connector gets hot from current flowing through it.
The best way to find where the volts are turning to heat is with the circuit on (yes a challenge on a starter circuit but don't think we have that here) and probing on both sides of the suspect connector. That is why the probes are pointed, so you can pierce the insulation with just a tiny hole while the circuit is in operation. set your volt meter to less than 2 volts range.
On hunter starting circuits there are something like 11 connectors between the batter + and -. Now if each only contributes 0.33 volts drop; 11*0.33=3.63, 12.6-3.63=8.37 volts available across the starter solenoid. I know for a fact that they take at least 9.5 to operate the solenoid and 0.33 volts drop in a connector is not horrible. Just when you add them all together they make a difference. so you might want to consider the possibility that it is not just one high resistance spot but many "slightly" high resistance spots.
The best way to find where the volts are turning to heat is with the circuit on (yes a challenge on a starter circuit but don't think we have that here) and probing on both sides of the suspect connector. That is why the probes are pointed, so you can pierce the insulation with just a tiny hole while the circuit is in operation. set your volt meter to less than 2 volts range.
On hunter starting circuits there are something like 11 connectors between the batter + and -. Now if each only contributes 0.33 volts drop; 11*0.33=3.63, 12.6-3.63=8.37 volts available across the starter solenoid. I know for a fact that they take at least 9.5 to operate the solenoid and 0.33 volts drop in a connector is not horrible. Just when you add them all together they make a difference. so you might want to consider the possibility that it is not just one high resistance spot but many "slightly" high resistance spots.
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