Ford F-150/F-250: How to Replace Spark Plug Wires

Bad spark plug wires can affect your truck's performance in various ways. Replacing them routinely will keep your Ford F-150 or Super Duty running smoothly.

By Makeda - October 9, 2014

This article applies to the Ford F-150 (2004-2014) and F-250 Super Duty (2005-2014).

When is it time to replace your spark plug wires? When you notice erratic engine combustion, engine hesitation, reduced engine power, or the engine surges while shaking when a car is idle. Ignoring these symptoms over a period of time can cause your Ford F-150 or Super Duty to stall out and not turn over. Although this is not a major issue, it can be unsafe if this were to happen on a highway or in less than perfect weather conditions.

Material

  • Spark plug wire set
  • Wrench (10 mm)
  • Spark plug wire removal tool
  • Dielectric grease

Pro-Tip

Before beginning the job, run your car without lights to see if you notice electrical arcs or a snap-crack sound for a high-voltage electrical leakage. Another way to check is by using a well-insulated handled screwdriver along the side of every wire to see if it arcs. To ensure your safety, avoid buying high performance wires to prevent radio waves in the electric under your hood.

Step 1 - Disconnect your battery

Figure 1. Remove the battery cable.

Open your hood. After the engine has cooled, use your 10 mm wrench to remove the negative battery cable (black). You want to do this to avoid any unexpected shocks while working on your electrical system.

Step 2 - Remove the old wires

  • Figure 2. Spark plug wire removal tool.

  • Figure 3. Spark plug wires.

Use a spark plug wire removal tool to remove the old wires.

Step 3 - Install new wires

Figure 4. Install the new wires.

Install the new wires in the same order as the old ones. Make sure to use the dielectric grease on the new wire using a small flat-head screwdriver. Also, be sure that the new wires are tightly connected to the spark plugs.

Step 4 - Install the battery cable

Figure 5. Install the battery cable back on.

Be sure to reinstall the negative battery cable or your truck won't start.

Step 5 - Start your truck

Figure 6. Start your truck.

After making sure they are all tight, connect the battery cable and start your truck. The start up should be smooth and jitter free.

Featured Video: How to Replace Spark Plug Wires in F-150/F-250

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