Is the starter engaging or it's only clicking? Try pulling the starter out
and testing it; connect a set of booster cables (red to the + and black
anywhere on the starter where you can put the clamp), then use a jumper wire
(a piece of regular automotive wire, 14 gauge, and 2 aligator clips works
well) from the + side and touch the connector on the solenoid where the
thinner wire is normally connected, and the starter should run (put your
foot on it or have a helper hold it down, they tend to jump a little when
they spin).
If it only clicks, the solenoid is usually the problem, the clicking is the
piston inside moving, but may not be making contact, or the starter itself
is faulty. To test further, put a test light on the wire going from the
solenoid to the starter, when the solenoid clicks, it should light, meaning
power is going to the starter, if it doesn't light, no power is going to the
starter. Light on, starter is the problem, light not on, solenoid is the
problem.
If it does engage but doesn't turn over, check the wires to the starter for
bad connections (had one where the wire was corroded inside the housing, but
looked ok from the outside). To check, connect booster cables from the
battery to the + side of the starter, and ground to the starter body, if it
now turns over, one of the wires from the battery is bad, check one at a
time to find which.
Ed B

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