Avalanche, Sierra, Silverado, C&K Series, 1999-2005

Ignition Coil

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Removal & Installation



  1. Tag and unplug the wiring connectors from the coil and the coil wire.
  2.  
  3. Unfasten the retainers securing the coil bracket and 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.

    Click image to see an enlarged view

    Fig. Ignition coil mounting-4.3L engines

  8.  

To install:


NOTE
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 and bracket to the manifold. Tighten the retainers until they are snug.
  4.  
  5. Engage the coil wire and the wiring connectors to the coil.
  6.  

  1. Tag and unplug the wiring connectors from the coil and the coil wire.
  2.  
  3. Unfasten the retainers securing the coil bracket and 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.

    Click image to see an enlarged view

    Fig. Ignition coil mounting-4.3L engines

  8.  

To install:


NOTE
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 and bracket to the manifold. Tighten the retainers until they are snug.
  4.  
  5. Engage the coil wire and the wiring connectors to the coil.
  6.  

5.7L Engine
  1. Remove the air cleaner assembly and nut.
  2.  
  3. Disconnect the electrical connectors.
  4.  
  5. Remove the ignition coil wire to the distributor.
  6.  
  7. Remove the studs holding the bracket and the ignition coil to the intake manifold.
  8.  
  9. Remove the bracket and the ignition coil.
  10.  
  11. Drill and punch out the two rivets holding the ignition coil to the bracket.
  12.  
  13. Remove the ignition coil from the bracket.

    Click image to see an enlarged view

    Fig. Ignition coil mounting-5.7L engine

  14.  

To install:


NOTE
A replacement ignition coil kit comes with two screws in order to attach the ignition coil to the bracket.

  1. Install the ignition coil to the bracket with the two screws.
  2.  
  3. Install the ignition coil and the bracket to the intake manifold with studs. Tighten the studs to 96 inch lbs. (11 Nm).
  4.  
  5. Install the ignition coil wire. The wire must not touch anything like the dip stick, rubbing will make a ground/short after time of use.
  6.  
  7. Install the electrical connectors.
  8.  
  9. Install the air cleaner assembly and nut.
  10.  

7.4L Engine
  1. Remove the air cleaner assembly.
  2.  
  3. In order to gain access to the ignition coil, relocate the engine wiring harness at the left rear side of the engine.
  4.  
  5. Disconnect the electrical connectors for the ignition coil and the ICM.
  6.  
  7. Remove the bolts retaining the coil to the intake manifold.
  8.  
  9. Remove the ignition coil.

    Click image to see an enlarged view

    Fig. Ignition coil mounting-7.4L engine

  10.  

To install:

  1. Install the ignition coil and the bolts to the intake manifold. Tighten the bolts to 22 inch lbs. (27 Nm).
  2.  
  3. Install the electrical connectors.
  4.  
  5. Install the ignition coil wire to coil. The wire must not touch anything like the dip stick. Rubbing will make a ground/short after time of use.
  6.  
  7. Relocate the engine wiring harness at the left rear side of the engine.
  8.  
  9. Install the air cleaner assembly.
  10.  

Testing



Tools Required: Digital Multimeter

  1. Remove the ignition Coil.
    WARNING
    Do not insert the digital multimeter probe into the ignition coil connectors. The female terminals could be deformed, resulting in intermittent operation. Only make contact with the front edge of the terminals.



    Click image to see an enlarged view

    Fig. Use the high scale. If the reading is not infinite, replace the coil

  2.  
  3. Connect an ohmmeter as shown. Use the high scale. If the reading is not infinite, replace the coil.

    Click image to see an enlarged view

    Fig. Use the low scale. The reading should be 0.1 ohms

  4.  
  5. Connect an ohmmeter as shown. Use the low scale. The reading should be 0.1 ohms. If not, replace the coil.

    Click image to see an enlarged view

    Fig. Use the high scale. If the reading is not 5-25k ohms, replace the coil

  6.  
  7. Connect an ohmmeter as shown. Use the high scale. If the reading is not 5-25k ohms, replace the coil.
  8.  


NOTE
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.

    Click image to see an enlarged view

    Fig. Ignition coil testing points

  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 0.1 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.  


NOTE
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.

    Click image to see an enlarged view

    Fig. Ignition coil testing points

  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 0.1 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.  

 
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