TEST 4: Testing The Continuity Of The Park-Lamps Circuit

Testing The Continuity Of The Park-Lamps Circuit. How To Test A No Park-Lamps Problem (1997, 1998 F150, F250, And Expedition)

So far, your test results have confirmed that:

  1. Fuse #7 is not blown (TEST 1).
  2. The TAN/WHT wire of the grey headlight switch connector has 10 to 12 Volts DC present (TEST 2).
  3. The park-lamps come ON when you jumpered female terminals 4 and 5 of the grey headlight switch connector (TEST 3).

Our last test will be to check the continuity of the park-lamp circuit inside the headlight switch.

We'll accomplish this test by doing a simple multimeter resistance test in Ohms mode.

Alright, let's get started:

  1. 1

    Place your multimeter in Ohms mode.

  2. 2

    With the headlight switch's knob in it's ‘headlight's off’ position.

    Your multimeter should now show NO continuity. This is usually represented on the multimeter's screen by the letters OL.

  3. 3

    Turn the headlight switch knob to the ‘park-lamps on’ position.

  4. 4

    Test for continuity between male spade terminals 4 and 5. See the photo above.

    If all is OK, your multimeter should register continuity (5 ohms or less).

  5. 5

    Turn the headlight switch knob to the ‘head-lamps on’ position.

  6. 6

    Test for continuity between male spade terminals 4 and 5. See the photo above.

    If all is OK, your multimeter should register continuity (5 ohms or less).

Let's take a look at what your test results mean:

CASE 1: The multimeter DID NOT register continuity. This tells you that the headlight switch is defective and needs to be replaced.

CASE 2: The multimeter registered continuity. This test result tells you that the park-lamps circuit, inside the headlight switch, is OK.

Where To Buy The Headlight Switch And Save

The following links will help you comparison shop for the headlight switch on your 1997-1998 Ford F150, F250, and Expedition:

More 4.6L, 5.4L Ford Diagnostic Tutorials

There are quite a few tutorials for the 4.6L and 5.4L equipped Ford F150, F250 pick-ups and Expedition SUV. You can check them out in this index:

  1. Ford 4.6L, 5.4L Index of Articles.

Here's a small sample of the tutorials you'll find in the index:

  1. How To Clean The Ford MAF Sensor (Ford 4.2L, 4.6L, 5.4L).
  2. How To Test The Fuel Injectors (1997-2002 4.6L F150).
  3. How To Test The Ford EGR Valve EGR Vacuum Solenoid, DPFE Sensor.
  4. How To Test The Ford MAF Sensor (4.2L, 4.6L, 5.4L).
  5. How To Test The 4.6L, 5.4L Ford Throttle Position Sensor (TPS).
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