How To Test: The Headlight Switch (Ford 4.9L, 5.0L, 5.8L)

Testing the headlight switch on your Ford pickup (SUV or van) isn't hard.

In this tutorial, I'll show you how to find out if the headlight switch is causing a ‘No Headlights’ or a ‘No Park Lamps’ condition.

NOTE: This tutorial covers quite a bit of Ford vehicles since the same headlight switch fits them all. To find out if this tutorial applies to your specific Ford vehicle, take a look at the ‘Applies To:’ box on the right column.

You can find this tutorial in Spanish here: Cómo Probar: El Interruptor de las Luces Delanteras (Ford) (at: autotecnico-online.com).

Headlight Switch Troubleshooting Basics

Here's a description of all of the headlight pins:

Headlight Switch & Connector Pin Out
Pin	Wire Color	Description
B1	Black w/ Orange stripe	Battery (+)
B2	Tan w/ White stripe	Battery (+)
D1	Lt Green w/ Yellow stripe	Power (+) for interior lamps
D2	Black w/ Pink stripe	To all interior lamps
H	Red w/ Yellow stripe	To headlight dimmer switch
I	White w/ Lt Blue stripe	To instrument panel lamps
IGN	Yellow w/ Black stripe	Battery (+)
R	Brown	To exterior lamps
DN	Orange w/ Black stripe	To radio illumination lamps

NOTE: The colors of the wires (above) may not be the ones coming out of the headlight switch connector in your particular Ford vehicle but the circuit (pin) descriptions will be the same.

Testing the headlight switch simply involves testing the continuity of certain circuits.

To be a bit more specific, you'll be using a multimeter in Ohms (Ω) and probing between to terminals (on the headlight switch itself) to see if there's continuity between them.

If there's no continuity between them, then that circuit is bad and the headlight switch on your Ford pickup (SUV or van) has to be replaced.

NOTE: You'll need to remove the headlight switch to test it.

• The two pins that complete the circuit for the headlights are:
  • pin B1
  • pin H
• The two pins that complete the circuit for the park lamp are:
  • pin B2
  • pin R

Melted Ford Headlight Switch Connector

Melted headlight switch connectors (and headlight switches) are a very common problem on Ford vehicle's equipped with this type of headlight switch. This problem will cause the headlights or park lamps to stop working.

There's a very good chance that this is exactly what has happened in your particular Ford vehicle.

So, before you start any of the tests in this tutorial, you'll need to see if this has happened in your particular case.

If you do find that the headlight switch connector is melted, you'll need to replace both the headlight switch and the connector. You can buy them both here:

Start Here: Testing The Headlight Switch

Depending on what issue you're having with your head lights (no headlights or no park lamps), your starting point will be in one of two different tests.

NOTE: Before starting any of the tests below, take a look at this section: Melted Ford Headlight Switch Connector.

Alright, depending on what problem you're trying to solve, here's your starting guide

No Headlights

1. The first test involves jumpering pins B1 and H and checking that the headlights turn on.
   • For this test, go to: TEST 1: Jumpering The Headlight Circuit.
2. The second test involves checking the continuity between pins B1 and H of the headlight switch itself.
   • For this test, go to: TEST 2: Testing The Continuity Of The Headlight Circuit.

No Park Lamps

1. The first test involves jumpering pins B2 and R and checking that the park lamps turn on.
   • For this test, go to: TEST 3: Jumpering The Park Lamp Circuit.
2. The second test involves checking the continuity between pins B2 and R of the headlight switch itself.
   • For this test, go to: TEST 4: Testing The Continuity Of The Park Lamp Circuit.