Here's a general outline. Specific steps and location will vary depending on your exact engine (e.g., 5.7L, 4.3L). Consult a repair manual specific to your GMC Sierra's year, engine, and model for detailed instructions and diagrams. This is crucial to avoid mistakes.
Before You Begin:
* Safety First: Disconnect the negative battery cable before starting any work on the ignition system.
* Repair Manual: Obtain a factory service manual or a reputable aftermarket repair manual specific to your vehicle. This will provide detailed diagrams and torque specifications.
* Tools: You'll likely need basic hand tools (sockets, wrenches, screwdrivers), possibly a torque wrench, and possibly a multimeter to test the new pickup coil.
General Steps (Consult your repair manual for specifics):
1. Locate the Pickup Coil: The pickup coil is usually located on the distributor (if your engine has one) or directly on the engine block near the crankshaft position sensor. Your repair manual will show the precise location.
2. Disconnect the Old Pickup Coil: Carefully disconnect the electrical connectors from the old pickup coil. Take pictures or make notes to remember the wiring configuration.
3. Remove the Old Pickup Coil: Depending on the location and design, this might involve removing screws, bolts, or clips holding it in place. Again, your repair manual is essential here.
4. Install the New Pickup Coil: Carefully install the new pickup coil, ensuring it's seated correctly in its mounting location. Tighten all screws or bolts to the manufacturer's specified torque.
5. Reconnect the Electrical Connectors: Connect the new pickup coil's electrical connectors, ensuring they are securely attached. Refer to your pictures or notes from step 2.
6. Reconnect the Battery: Reconnect the negative battery cable.
7. Test the Installation: After reconnecting the battery, attempt to start the engine. If it doesn't start, there may be an issue with the installation, a faulty new pickup coil, or another problem. You may need to use a multimeter to test the continuity and resistance of the new pickup coil to confirm it's functioning correctly. Again, your repair manual may have testing procedures.
Important Considerations:
* Distributor-less Ignition Systems: If your truck has a distributor-less ignition system (more common on V8s), the pickup coil might be integrated with the crankshaft position sensor. Replacing this is significantly more complex and may require specialized tools.
* Torque Specifications: Use a torque wrench to tighten fasteners to the proper specifications to avoid damaging the engine or the pickup coil.
* Gaps and Alignment: Some pickup coils require precise alignment and/or specific air gaps. Your repair manual will provide details on this.
* Electrical Testing: Using a multimeter to check the resistance of the new pickup coil and its wiring connections can help ensure proper function before trying to start the vehicle.
This is a simplified overview. Always consult a repair manual specific to your vehicle before attempting this repair. Working with the ignition system can be dangerous if not done correctly, so if you're not comfortable, seek professional help.
