Where is the ballast resistor located on a 1987 Dodge D150?

The ballast resistor on a 1987 Dodge D150 is typically located in the wiring harness, near the ignition coil. It's not usually a separate, easily identifiable component like a large resistor on its own. You'll likely find it integrated into the wiring loom somewhere around the coil, often secured with zip ties or held in place by the harness itself.

Because it's integrated and not a standalone part, visually identifying it can be tricky. You might need a wiring diagram specific to your truck's engine to pinpoint its location within the harness. A wiring diagram will also show you the color codes of the wires connected to the ballast resistor, which will help you identify it by tracing those wires back from the coil.