Sounds like bad cable connections going to the battery or possibly a bad neutral safety switch cable going to the auto trans. Try turning the headlights on and then try to start it. If the lights go out, then it is most likely the cable connections at the battery. If your battery cables have replacement ends, take them off and apart and clean the clamp connections. Try again, if the head lights stay on bright then it can be the starter or the neutral safety switch cable. To check the switch cable move the shifter up and down the range and watch the switch on the firewall for movement. Be careful a malfunction of the cable could allow the car to start in gear! If this seems ok, the starter may be at fault. You can activate the starter directly by running a small jumper wire(positive) directly to neutral safety switch plug. Pull the plug off and touch the jumper to the purple wire (top or bottom end socket). If yours is a standard transmission you can also jump directly to the starter by touching the (positive) directly to the "G" (small screw) on the thermal time switch.
If you still have no luck, check the wire connections at the terminal block on the right side of the oil pan, then the connections at the starter.
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