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Dodge Ram 2002-2008: Fuse Box Diagrams

The fuse box helps provide reliable power at the proper amperage to various electrical components on your Dodge Ram. These include lights (running lights, back-up lights, headlights), heater, A/C, and power locks. This part, also known as a Power Distribution Center (PDC), can have problems on the Dodge Ram. Thankfully, most solutions are simple and of the DIY variety.

By Richard Bowen - July 15, 2015

This article applies to the Dodge Ram 3rd Generation (2002-2008).

Not only are there occasional issues regarding the fuse box itself, but Dodge Ram owners sometimes cannot find the fuse box diagram to determine where to look for the faulty fuse or relay. The diagram is supposed to be located under the fuse box lid (you have to turn the lid over to see it). If it is not there, you can check your owner's manual. You can also check with your local dealer to see if s/he has a diagram for your truck. In the 3rd generation Dodge Ram there is only one fuse box, which is located under the hood on the driver's side.

If you cannot locate the fuse box diagram for your vehicle in any of those places, then read on as this article will provide the tips.

Fuse Box Diagram and Key

The diagram and the following key (Figures 1 and 2) may match your vehicle's fuse box.

  • Figure 1. Fuse box diagram.
  • Figure 2. Key to fuse and relay location.

Service manuals also provide fuse box diagrams. Click here for a link to the downloadable 2002 to 2008 Dodge Ram service manuals.

Blown Fuse or Relay

Most fuse boxes contain both fuses and relays. If one of the electrical components on your Ram is not working properly, you may have a bad fuse or a bad relay, depending on which of these controls the electricity going to the problem component. Fuses are square plastic "tabs" that come in a variety of colors. A relay is metal and rectangular in shape.

The most obvious problem for lights or other electrical components not operating is a blown fuse or bad relay.

To check for a bad fuse:

  1. Remove the fuse box cover.
  2. Reference the fuse diagram to find the fuse for the problem component.
  3. Pull the fuse out of the box.
  4. Visually inspect the fuse. If the metal inside the fuse is separated, that fuse is blown. Replace it with a new fuse with the same amperage.

To test for a bad relay:

  1. Try to find a relay in the fuse box with the same amperage as the relay supplying power to the electrical component that is not functioning properly.
  2. If you find one, unplug it. (Alternatively, if you don't find a relay with the same amperage in the box, buy one with the same amperage as the one supplying electricity to the component that is not operating properly.)
  3. Unplug the relay that controls the electricity to the electrical component that is not functioning properly, and replace it with a relay with the same amperage. Check to see if the faulty electrical component now works.
  4. If the component works now, you know the relay is bad. Replace the relay.
  5. If the component is still not functioning properly, the relay is OK. Check one of the solutions below (under Other Issues).

Other Issues

Corrosion in the Fuse Box

Some Ram owners report corrosion on the circuit board in the fuse box after getting water in the engine compartment. If this happens, you can replace the fuse box and then apply clear lacquer or a silicone sealer around the area to avoid problems in the future.

Check Connectors Under the Fuse Box

Occasionally, the connectors underneath the fuse box come loose. Check that they are secure.

Key Must Be in "Run"

On some trucks, you must turn the ignition key from "Off" to the "Run" or "On" position for the fuses to receive power. Put your Dodge Ram's ignition key in the "Run" position and see if the fuse box has power.

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