Are you sure about the engine size and SLE? Didn't see a 4.6L jimmy? The purple wire at the starter solenoid should be hot with key in the crank position. If it isn't, backtrack the circuit. Any testing at the starter, make sure the tranny is in park or neutral and the e-brake is set.
You need to make sure the battery has a full charge and the connections are clean and tight. The generic spec for a fully charged battery is around 12.6 volts.
Wednesday, May 25th, 2011 AT 8:49 PM