1. Check the Fuses and Relays:
* Ignition System Fuse: Locate the fuse box (usually under the hood or inside the cabin) and check the fuse specifically for the ignition system. The manual will show you which fuse is responsible. A blown fuse is the easiest fix.
* Ignition System Relay: Many systems use relays. Check your owner's manual for the location and function of the ignition system relay (sometimes called the ignition coil relay). A bad relay can be swapped with a known good one for testing.
2. Inspect the Wiring:
* Coil Power Wire: Trace the power wire from the coil back to its source (usually the ignition switch or a relay). Visually inspect the wire for any signs of damage, fraying, corrosion, or broken connections. Pay close attention to where the wiring harness may rub against metal parts.
* Ground Connection: A poor ground connection can prevent the coil from receiving power. Check the ground wire connected to the coil and engine block. Clean any corrosion and ensure a tight connection.
* Connections: Carefully inspect all connectors along the wire's path, ensuring they are securely plugged in.
3. Test for Power:
* Power at the Coil: With the ignition key turned to the "ON" position (not cranking), use a multimeter to test for power at the coil's positive (+) terminal. If there's no power, the problem is upstream of the coil (fuse, relay, wiring).
* Power at the Relay: If you suspect the relay, test for power at the relay's input and output with the ignition on. If power is present at the input but not the output, the relay is faulty.
* Power at the Ignition Switch: This requires more advanced diagnostic skills and may involve testing the output of the ignition switch itself.
4. Consider the Crankshaft Position Sensor (CKP):
* The CKP sensor is crucial for triggering the ignition system. A faulty CKP sensor won't send the signal needed to energize the coil. This is less likely to cause a complete lack of power, but it might be worth checking if other steps yield no results.
5. The Coil Itself:
* While less likely to be the sole cause of *no* power, a faulty ignition coil can certainly prevent sparking. Testing the coil requires a bit more specialized equipment (usually an ohmmeter to check resistance).
Important Notes:
* Safety First: Disconnect the negative battery terminal before working on any electrical components.
* Owner's Manual: Consult your owner's manual for specific fuse and relay locations and diagrams.
* Professional Help: If you're uncomfortable working with car electrical systems, it's best to seek professional help from a qualified mechanic. Improper repairs can lead to further damage.
By systematically checking these areas, you should be able to pinpoint why your 1999 Dodge Ram 5.2L coil isn't receiving power. Remember to test each component methodically to isolate the problem.
