Dandy. First try starting the engine with the shifter in "neutral". If that works, suspect the neutral safety switch.
Observe if the red "Brake" warning light on the dash turns on when you turn the ignition switch to "crank". If it does not, the ignition switch is out of adjustment. It is half way down on the side of the steering column and will shift position if the mounting screws work loose.
Next, unplug the red / blue wire from the starter solenoid on the inner fender. Momentarily connect a jumper wire from that small stud to the large one that is connected to the battery's positive post. Be sure the transmission is in "park" or the ignition switch is off. The solenoid should click loudly, and the engine should crank. If it doesn't crank, the solenoid is bad or it isn't mounted solidly to a good ground.
If the starter cranks the engine with that jumper wire, have a helper turn the ignition switch to "crank" while you test for voltage on that red / blue wire. A test light will be more accurate than a digital voltmeter for this test. If no 12 volts appears, you'll need to find the neutral safety switch and take some readings on it.
That switch is on the side of the transmission and should have an eight pin connector, probably with five wires. Back-probe through the back of the connector on the two red / blue wires. Both should have 12 volts when your helper turns the ignition switch to "crank". If one of them does not, shift to different gears and see if it shows up. If you always only get 12 volts on one of those wires, use a stretched-out paper clip to jump those two wires together. The starter should work now in any gear, so be careful in case the engine starts in gear. If that doesn't work, the jumper is likely not making good contact with the terminals. Disconnect that plug, then jump those two wires on the terminal end.
If you don't get 12 volts to either red / blue wire at the neutral safety switch, double-check that the clip lead for the test light is making solid contact. Next, either the ignition switch is bad or there's a break in a wire to or from it. There's two yellow wires on that switch. Both should have 12 volts all the time. If you do find that, check for 12 volts on the red / blue wire when you turn the switch to "crank". If you don't get 12 volts on the red / blue wire, the switch is bad. If you do get 12 volts, but not at the neutral safety switch, that wire has a break in it.
Thursday, January 12th, 2017 AT 5:39 PM