Ignition Coil

TESTING

1. Connect an ohmmeter across the coil primary terminals and check resistance on the low scale. Resistance (@ 68°F; 20°C) should be:

   Pickups:

   • 1987–89 B2200 carbureted: 1.0–1.3 ohms
   • 1990–93 B2200 injected: 0.81–0.99 ohms
   • 1987–88 B2600: 1.0–1.3 ohms
   • 1989 B2600i; Point 1: 0.77–0.95 ohms ; Point 2: 0.9–1.1k ohms
   • 1990–93 B2600i: 0.81–0.99 ohms

     Fig. 1: Ignition coil primary resistance test — 2.2L carbureted engine (left), 2.6L fuel injected engine (right)

     Fig. 2: Checking the primary ignition coil reesistance — 3.0L engine

   MPV

   • 2.6L engine; Point 1: 0.77–0.95 ohms ; Point 2: 0.9–1.1k ohms
   • 1989–91 3.0L engine: 0.81–0.99 ohms
   • 1992–93 3.0L engine: 0.72 — 0.88 ohms
2. If resistance is much higher, replace the coil.
3. Check the coil secondary resistance.Connect an ohmmeter across the distributor side of the coil and the coil center tower. Read resistance on the high scale. Resistance at 68°F; 20°C) should be:

   Pickups

   • 1987–88 B2200: 6–30k ohms
   • 1987–88 B2600: 10–20k ohms
   • 1989–93 B2200 and B2600i: 6–30k ohms

     Fig. 3: Ignition coil secondary resistance test — Coil for carbureted engine shown

   MPV

   • 1989–93 2.6L engine — Point 1: 0.77–0.95 ohms ; Point 2: 0.9–1.1k ohms
   • 1989–91 3.0L engine: 0.81–0.99 ohms
   • 1992–93 3.0L engine: 0.72–0.88 ohms
4. If resistance is much higher, replace the coil.
5. Disconnect the high tension wire and move the connector leading to the negative terminal over to the metallic connector inside the coil tower. Set the ohmmeter to the X1000 scale. Resistance must be:

   Pickups

   • 1987–88 B2200: 6–30k ohms
   • 1987–88 B2600: 10–20k ohms
   • 1989 — 93 B2200 and B2600i: 6–30k ohms

     Fig. 4: Checking the ignition coil secondary resistance — 3.0L engine (MPV)

   MPV

   • 2.6L engine; Point 1: 0.77–0.95 ohms ; Point 2: 0.9–1.1k ohms
   • 1989–91 3.0L engine: 0.81–0.99 ohms
   • 1992–93 3.0L engine; 0.72–0.88 ohms
6. You can also check for bad coil insulation by measuring the resistance between the coil (-) primary connection and the metal body (case) of the coil. If resistance is less then 10m ohms, replace the coil. This test may not be entirely satisfactory unless you have a megaohm tester that records 500 volts. If the tests below do not reveal the problem and, especially, if operating the engine at night may produce some bluish sparks around the coil, you may want to remove the coil and have it tested at a diagnostic center.
7. If the coil resistances are not as specified, replace the coil.

   If the coil tests out ok, replace the igniter and pickup coil. However, you should make sure before doing this work that there are no basic maintenance problems in the secondary circuit of the system, since it is often impossible to return electrical parts. We suggest that before you replace the igniter and pickup coil, you carefully inspect the cap and rotor for carbon tracks or cracks and disconnect the wires and measure their resistance with an ohmmeter. Resistance should be 16k ohms per 3.28 ft. (1m). Also, check for cracks in the insulation. Replace secondary parts as inspection/testing deems necessary before replacing the igniter and pickup coil.