GM S-Series Pick-ups and SUV's 1994-1999 Repair Guide

Ignition Coil

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TESTING



See Figure 1



Click image to see an enlarged view

Fig. Fig. 1: Ignition coil testing-Distributor Ignition (DI) systems

Make sure the ignition switch is

OFF

  1. Tag and disconnect the wires from the ignition coil.
  2.  
  3. Using a digital ohmmeter set on the high scale, probe the ignition coil as shown in Step 1 of the accompanying illustration.
  4.  
  5. The reading should be infinite. If not replace the coil.
  6.  
  7. Using the low scale of the ohmmeter, probe the ignition coil as shown in Step 2 of the accompanying illustration. The reading should be 0.2-0.5 ohms, if not replace the coil.
  8.  
  9. Using the high scale of the ohmmeter, probe the ignition coil as shown in Step 3 of the accompanying illustration. The reading should be 5k-25k ohms, if not replace the coil.
  10.  
  11. Reconnect the wires to the ignition coil.
  12.  

REMOVAL & INSTALLATION



  1. Tag and disengage the wiring connectors from the coil and the coil wire.
  2.  
  3. Unfasten the retainers securing the coil bracket or coil to the manifold.
  4.  
  5. Remove the coil and bracket and drill out the two rivets securing the coil to the bracket.
  6.  
  7. Remove the coil from the bracket.
  8.  

To install:

The replacement coil kit may come with the two screws to attach the coil to the bracket. If not, you must supply your own screws.

  1. Fasten the coil to the bracket using two screws.
  2.  
  3. Fasten the coil bracket or to the manifold. Tighten the retainers to 20 ft. lbs. (27 Nm).
  4.  
  5. Engage the coil wire and the wiring connectors to the coil.
  6.  

 
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