Where is the ballast resistor located on a 1989 dodge 100 pickup?

On a 1989 Dodge D100 pickup, the ballast resistor is typically located on the firewall, near the ignition coil. However, it's not always visually obvious and might be hidden behind components or wrapped in heat shielding. You might need to do some careful searching in that area.

It's a relatively small, usually ceramic resistor, often with wires attached. A wiring diagram for your specific year and engine would be extremely helpful in pinpointing its exact location. You can often find these diagrams online through sites specializing in automotive repair manuals.