Genuine GMC Jimmy Ignition Coil

GMC Jimmy Ignition Coil Parts Questions & Experts Answers

• Distributor Ignition Pickup
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  Q: How to check and replace the pick-up coil on Chevrolet Blazer,S10,GMC Jimmy and Sonoma?

  A: To check the ignition coil, start by connecting one lead of an ohmmeter to the terminal of the ignition coil lead and the other lead to the ground. Flex the leads by hand to check for intermittent opens, and the ohmmeter should always indicate infinite resistance. If it doesn't, the ignition coil is defective and needs to be replaced. Next, connect the ohmmeter leads to both terminals of the ignition coil lead and flex the leads by hand again. The ohmmeter should read a steady value between 500 and 1,500 ohms as the leads are flexed. If it doesn't, the ignition coil is defective and should be replaced. To remove the ignition coil, start by detaching the cable from the negative terminal of the battery. Then, remove the Distributor cap and rotor, and if necessary, remove the distributor itself. Remove the spring clip from the distributor shaft and mark the distributor tang drive and shaft for reassembly. Set the distributor in a vise with a shop rag to protect the shaft, and use a hammer and punch to remove the roll pin from the distributor shaft and gear. Lift the ignition coil assembly straight up and remove it from the distributor, noting the order in which the pieces were removed. Reassembly is the reverse of disassembly.
• Ignition Coil
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  Q: How to check and remove the Ignition Coil on Chevrolet Blazer,S10,GMC Jimmy and Sonoma?

  A: To check the High Energy Ignition System (HEI), begin by disconnecting the battery's negative terminal. Test the coil for opens and grounds. On the high scale, connect the ohmmeter leads; it should show a very high or infinite resistance value. On the low scale, check the coil's primary resistance, which should indicate a very low or zero resistance value. Also, check the coil's secondary resistance on the high scale; it should not show an infinite resistance. If any values are off, replace the coil. For removal, unplug the coil's high-tension wire and electrical leads, and remove the mounting nuts to take out the coil. The installation process is the reverse of removal.