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Dodge Ram 1994-2008: Why Won't My Truck Start?

You are ready to take on the day until you reach the cabin of your truck and try to start the car.

By Piyush Kayastha - July 14, 2015

This article applies to the Dodge Ram 2nd and 3rd Generation (1994-2008).

The problem of a "no start" condition can be either a relatively easy one or a complicated one. Several factors go in to why a vehicle may not start. Several factors are to be considered when we think of what enables a vehicle to start in the first place. With the combination of fuel, spark, and compression, it creates that familiar sound of your engine firing up. It is also good to know that weather can affect your car's ability to start the next morning. But, what has occurred on the day that you are unable to hear that familiar sound? It is wise to diagnose this issue in parts to understand where the failure has occurred and address it accordingly.

Note

The DIY Cost varies depending on the cause:

  • New PCM - $289+
  • Per spark plug - $4.50
  • Block heater - $120-455
  • Fuel filter - $65

Materials Needed

  • Utility torch
  • Spark plug removal tool
  • Flat tip screwdriver
  • Fuel pressure gauge
  • Compression test tool

Step 1 – Check for spark

If you have already tried to give the vehicle a boost with jumper cables and the vehicle is not producing spark, it is unable to ignite the fuel being sent to the cylinders when cranking.

  • Remove one spark plug wire.
  • Remove one spark plug and place it within the wire.
  • Have a friend hold the spark plug near the bare metal.
  • Crank the car and observe if spark flies from the plug to the bare metal.
  • Figure 1. Mid-spark.
  • Figure 2. Electrical ignition system.

Pro Tip

Safety first! Placing the spark plug in the metal holder of the wire grounds the spark plug. If you have recently serviced the truck for a tune up, you may also want to make sure the firing order of the wires is correct and that the distributor is set correctly.

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If you have spark, move on to Step 2. If you do not, replace the fouled plug and/or wire.

Step 2 – Check for fuel

If temperatures have been really cold, it's possible fuel is not making its way up to the cylinders for the spark plugs to ignite. It's possible that there may be water iced in the fuel lines. There could also be a situation of a clogged catalytic converter.

  • Remove the fuel pump relay.
  • Unplug the 12v coil wire.
  • Remove all spark plug wires and spark plugs.
  • Crank the motor a few times to remove excess fuel.
  • Connect the fuel pressure gauge to test fuel pressure regulator (FPR).
  • Crank the motor to test the fuel pressure.
Figure 3. Testing for fuel pressure.

Pro Tip

Some later model trucks also have a "port" that you can hook up the gauge to test at the fuel rail. Also, you can unplug the front O2 sensor to the catalytic converter and try to see if the car/truck starts.

Featured Video: Testing Fuel Pressure

If the FPR shows no fuel pressure, the lines coming from the fuel filter and/or the fuel filter may be frozen or need replacement. If there is fuel pressure, move on to Step 3.

Step 3 – Check compression

If you have determined that the vehicle does indeed have spark and fuel, we'll need to make sure there is air compression at each cylinder.

  • Remove #1 spark plug and wire.
  • Connect the compression test tool.
  • Have someone crank the car and watch the gauge on the tool.
  • Repeat the test for the remaining cylinders.
Figure 4. Compression testing the cylinders.

Featured Video: Testing Compression

Pro Tip

Make sure to remember or label the order of spark plugs wires before re-installing. The compression should read 49 psi per cylinder.

If the vehicle has no compression, one or more of the cylinders may need servicing or further repair and diagnosis. If the vehicle does have compression, move on to Step 4.

Step 4 – Replace PCM

It has been found that under extreme cold temperatures, the PCM (Primary Control Module) a.k.a the "car's computer" cannot operate under severe cold until it has reached a "warm" temperature. It may not send the signal to the relays to turn on and allow fuel to flow and spark to fly. It may also not be possible to scan the car for codes if the PCM is faulty.

  • Attempt to warm up PCM by removing from vehicle and bringing to a warm environment, or using utility torch carefully.
  • Attempt to scan truck for codes using diagnostic tool.
  • Replace PCM with new one.
Figure 5. PCM overview.

Pro Tip

At this point, a battery boost could "wake up" the PCM, but it would still require an eventual replacement. When using the torch, take extreme care not to burn or melt any plastic or wires.

(Related Article: Dodge Ram 1994-2001: How to Reset PCM - DodgeForum.com)

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