- Turn the ignition key OFF . Disconnect the negative battery cable. Then, carefully remove the retaining nuts and disconnect the two coil primary leads. Wrap the positive (+) lead in electrician's tape or otherwise ensure that it cannot accidentally ground during the test.
- Run a jumper wire from the battery positive (+) terminal directly to the coil positive (+) terminal. Run the jumper wire incorporating the capacitor from the coil negative terminal to a good ground. Reconnect the battery negative cable. Fasten one end of the remaining standard jumper wire in a position where the clip cannot ground. Then connect the other end of it to the coil negative terminal. Turn ON the ignition key.
- Unclip the coil high tension lead from inside the distributor cap and pull it out. Hold the distributor end of the lead 1 / 4 in. (6mm) from a good ground. Ground the standard jumper wire coming from the coil negative terminal.
- Break the ground in the standard lead coming from the coil negative as you watch for spark. The coil should produce a hot, blue-white spark. Repeat the test looking at the coil tower. If sparks are visible there, replace the ignition wires if the rubber boots are deteriorated, or the coil, if the tower is burned and tracked.
- If the coil tower and wire boots are okay, and this test fails to produce a spark, replace the coil.
On 1987-89 cars, you can confirm the problem with an ohmmeter. Turn OFF the ignition switch, and disconnect the negative battery cable. With the coil primary wires still disconnected, test the resistance between positive and negative primary terminals. It must be 1.35-1.55 ohms. For secondary resistance, first determine whether the coil is a Chrysler Prestolite, Chrysler Essex, or Diamond brand coil by wiping off the coil and looking for appropriate lettering. Then, pull the high tension lead out of the coil tower and run the ohmmeter lead between the coil negative primary terminal and the brass connector down inside the tower. Resistance ranges must be as follows:
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Remove the coil wire.
- Tag the negative and positive wire leads to the coil.
- Remove the wire lead connections.
- Take off the wire leads from the coil.
- Loosen the mounting screw, then slide the coil from the mounting brace.
- Insert the coil into the mounting brace.
- Attach the wiring leads to the coil.
- Tighten down the brace if needed.
- Attach the coil wire.
- Connect the negative battery cable.