Where is the starter relay on a 2008 Dodge Cummins?
The starter relay on a 2008 Dodge Ram with a Cummins diesel is located in the engine bay’s power distribution center (the under-hood fuse/relay box). It’s typically labeled START or ST in that box.
Locate the starter relay
Typical location in the engine bay
Most 2008 Ram Cummins models use a central relay block known as the Power Distribution Center (PDC). The PDC is usually mounted in the engine compartment on the driver’s side, near the fender or along the radiator support. The lid often includes a diagram showing the START/STS relay position.
The following steps will help you locate the relay quickly in most 2008 Cummins-equipped Rams. Gather a flashlight and ensure the ignition is off before touching electrical components.
- Open the hood and locate the engine compartment fuse/relay box (Power Distribution Center). It’s typically on the driver’s side near the fender or along the top edge of the engine bay.
- Remove the PDC cover to view the circuit diagram printed on the underside and the relay layout.
- Look for a relay labeled START, STARTER, or ST; some boxes use abbreviations or color coding. If the label isn’t clear, follow the diagram to identify the correct relay.
- If you’re unsure, trace the wires from the starter solenoid back to the PDC to confirm the relay position.
With the relay identified, you’re ready to test or replace it as needed. If the label is unclear, refer to the owner's manual or the lid diagram for the exact position.
Testing and replacement
Safety and testing basics
Testing a starter relay involves basic voltage checks and continuity. For safety, disconnect the battery, and work with the ignition off before removing or manipulating electrical connectors.
The steps below outline how to test and replace the relay:
- Disconnect the negative battery terminal to prevent shorts.
- Remove the START relay from the PDC and test with a multimeter. Check for 12V at the coil terminals when the ignition is in the ON or START position, and verify continuity between the common and NO/NC contacts when energized.
- If the coil has no voltage, or there is no continuity when energized, replace the relay with the same amperage rating (commonly around 20–30A for the START relay in these boxes). Reinstall in the same position.
- Reconnect the battery and attempt to start the vehicle to confirm operation. If it still won’t start, further diagnostics may be needed (starter, wiring, ignition switch, or PCM).
Replacing a faulty starter relay in the PDC is a common fix for intermittent starting issues; always verify wiring and ensure no corrosion on connectors.
Summary
In a 2008 Dodge Ram with a Cummins engine, the starter relay sits in the engine bay's under-hood power distribution center, typically labeled START. By opening the PDC cover and following the diagram, you can locate, test, and replace the relay if needed. If the diagram is unclear or you’re not comfortable with electrical work, consult a qualified mechanic.
How to tell if the starter relay is bad?
But other systems like dashboard lights music systems and headlights are working fine. This complete lack of response. Often points to a bad starter relay.
Why won't my Dodge Ram 2500 diesel turn over?
The most common reasons a Ram 2500 won't start are a dead battery, an alternator problem, or failed starter. Battery: A weak or failing battery can result in difficulty starting the engine and electrical system malfunctions.
Where is the starter motor relay located?
Starting relay position
It might be in the power box (also called the fuse box), under the dash panel, or near the right fender. In most cars, you'll find it under the hood in a big box with a black cover. This is where all the car fuses and relays are kept.
Where is the relay on a 2008 Dodge Ram?
Relays on most dodge cars are under the left fender. Lift the car and remove the left front wheel ie battery side. Remove the fender cover and you will find a harness and relay assembly containing +_4 relays.
