Headlamp switch, how to replace

https://www.fixya.com/cars/t8706315-2003_gmc_yukon_xl_denali_low_beam

Drl only work in daytime not at night ???? Daytime running lamps are only suppose to work in day light hours . Low beam & high beams ? none of these work at night ?
Headlamps
The headlamps may be turned on in two different ways. First, when the driver places the headlamp switch in the HEADLAMP position, for normal operation. Second, with the headlamp switch placed in the AUTO position, for automatic lamp control (ALC). During ALC the headlamps will be in day time running lamp (DRL) operation in daylight conditions, or headlamp operation in low light conditions.
Headlamp ON/OFF control is determined by the body control module (BCM) by a signal on the headlamp switch on input circuit when the headlamp switch is in the HEAD position. When the headlamp switch is in the AUTO position, the BCM determines headlamps ON/OFF by the voltage from the ambient light sensor.
If the headlight switch is left in the ON position, the inadvertent power control feature will turn off the headlights approximately 10 minutes after the ignition switch is turned to the OFF position. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, or if the ignition switch is in the ACCY position, the headlights will remain on until turned off or the battery runs dead.
The high beam indicator is illuminated when the instrument cluster receives a class 2 serial data message from the BCM that the high beams are illuminated.

Do you know what the BCM is ? Do you know what DTC'S - diagnostic trouble code's are ?
DTC B2575
When the body control module (BCM) senses a request for low beam headlamp illumination, the BCM sends a ground signal to the low beam headlamp relay through the headlamp low beam relay control circuit. The headlamp low beam relay will apply voltage to illuminate the headlamps.

Low and High Beams Headlamps Inoperative
Step
Action
Yes
No
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference: Lighting Systems Connector End Views or Body Control System Connector End Views in Body Control System.
1
Did you perform the Lighting System Diagnostic System Check?
YES - Go to Step 2
NO - Go to Diagnostic System Check - Lighting Systems
2
Place the headlamp switch in the ON position.
Change the dimmer switch position from the high to low beam positions several times.
YES - Does the headlamp system operate normally?
NO - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 3
3
Are both high and low beam headlamps inoperative?
YES - Go to Step 4
NO - Refer to Headlamps Inoperative - Low Beams or Headlamps Inoperative - High Beams
4
With a scan tool, observe the headlamp switch parameter.
Does the scan tool indicate ACTIVE? YES - Go to Step 7
NO - Go to Step 5
5
Connect a test lamp between the ground circuit of the headlamp switch connector and battery positive voltage.
Does the test lamp illuminate?
YES - Go to Step 6
NO - Go to Step 9
6
Test the headlamps switch headlamps on signal circuit of the headlamp switch for a high resistance, an open, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 12
Go to Step 8
7
Inspect for poor connections to the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 12
Go to Step 10
8
Inspect for poor connections to the headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 12
Go to Step 11
9
Repair the ground circuit of the headlamp switch.
Did you complete the repair?
Go to Step 12
--
10
Important: Perform the setup procedure for the body control module.
Replace the body control module. Refer to Body Control Module Replacement
Did you complete the replacement?
Go to Step 12
--
11
Replace the headlamp switch. Refer to Headlamp Switch Replacement
Did you complete the replacement?
Go to Step 12
--
12
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 3

The headlamps are controlled by the BCM - body control module , do you know what that is ? The headlamp switch is a input to the BCM ,the BCM energizes relays to turn on the headlmps , low beam relay , high beam relay , DRL relay . These relay's are PCB - printed circuit board relay's ( non - serviceable ) If found to be bad the whole under hood fuse box would need to be replaced .
Low Beam Headlamp Operation
The low beam headlamps may be turned ON in 3 different ways:
• When the headlamp switch in the HEAD position for normal operations
• When the headlamp switch is in the AUTO position, for automatic lamp control (ALC)
• When the headlamp switch is placed in the AUTO position, with the windshield wipers ON in daylight conditions, after a 6 second delay
Battery voltage is applied at all times to the coil and switch sides of the LOW BEAM PCB Relay located in the underhood fuse block. When the headlamp switch is placed in the HEAD position, ground from G202 is applied through headlamps ON switch signal circuit to the body control module (BCM), signaling the headlamps ON request. In response to this signal, the BCM applies ground through the headlamp low beam relay control circuit energizing the low beam relay. With the relay energized, battery voltage is applied through the switch side of the relay, the left and right low beam fuses, and the low beam supply voltage circuits illuminating the low beam headlamps. Ground for the left headlamp is provided at G101 and the right headlamp at G100.

Do you know what B codes are ? BCM - DTC'S - diagnostic trouble codes , need a factory scanner or professional one to view these codes , not autozone or advance etc....Having a qualified repair shop check your vehicle would be your best bet.

DTC B2575 00: Headlamp Control Circuit

Circuit/System Description
The vehicle headlamps are controlled by the body control module (BCM) based on inputs from the headlamp switch and the turn signal/multifunction switch. The headlamp switch has four positions: Off, Auto, Park, and Headlamps. The default headlamp switch position is Auto, in which the BCM uses the ambient light sensor to determine when headlamps are needed. The Off portion of the headlamp switch is a momentary switch which overrides the automatic headlamps and will turn off the vehicle headlamps. When in the Off position, the headlamp switch grounds the headlamp switch headlamps off signal circuit, prompting the BCM to turn off the headlamps. The Park position of the headlamp switch will only illuminate the vehicle parking lamps. The Headlamp position of the headlamp switch will illuminate both the parking lamps, as well has the headlamps. With the headlamp switch in the Headlamp position, the headlamp switch headlamps on signal circuit is grounded, prompting the BCM to turn on the headlamps, regardless of other factors such as ambient light.
The headlamp high beams are controlled through the flash to pass switch and the headlamp dimmer switch, both located in the turn signal/multifunction switch. The flash to pass switch is a momentary type switch, designed to illuminate the high beams as long as the switch is held. With the switch closed, the flash to pass switch signal circuit is grounded, prompting the BCM to turn on the high beam lamps. The headlamp dimmer switch allows the operator to select between full time high or low beam operation. Unlike the flash to pass switch, it is not a momentary switch. When the headlamp dimmer switch is in the high beam position, the headlamp dimmer switch high beam signal circuit is grounded. This prompts the BCM to turn on the high beam lamps.
The BCM controls the headlamps based on the inputs explained above. When a low beam request is received, the BCM grounds the headlamp low beam relay control circuit. This energizes the coil in the LOW BEAM PCB relay, causing the relay switch to close. This then applies B+ to both low beam headlamps through the LT LO BEAM and RT LO BEAM fuses, illuminating the low beam headlamps. When a high beam request is received, the BCM grounds the headlamp high beam relay control circuit. This energizes the coil in the HIGH BEAM PCB relay, causing the relay switch to close. This then applies B+ to both high beam headlamps through the LT HI BEAM and RT HI BEAM fuses, illuminating the high beam headlamps

Headlamp Low or High Beams Always On

1

Was the Lighting System Diagnostic System check performed?
Go to Step 2
Go to Diagnostic System Check - Lighting Systems

2

1. Turn the ignition switch to the OFF position.
2. Turn the headlamp switch to the OFF position.

Are any of the headlamps on?
Go to Step 3
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3

Disconnect the headlamp switch.
Are the headlamps on?
Go to Step 4
Go to Step 8

4

Disconnect the multifunction turn signal switch.
Are the headlamps on?
Go to Step 6
Go to Step 5

5

Test for a short to battery positive voltage in the headlamp switch signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES Go to Step 10
NO Go to Step 7

6

Test for a short to battery positive voltage in the headlamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES Go to Step 10
NO Go to Step 9

7

Replace the multifunction turn signal switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.
Did you complete the replacement?
YES Go to Step 10

8

Replace the headlamp switch. Refer to Headlamp Switch Replacement .
Did you complete the replacement?
Go to Step 10

9

Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.
Did you complete the replacement?
Go to Step 10
--

10

Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 2

Well Jeni there are a few thing's that could be wrong , the headlamp switch , the BCM -body control module -a electronic control module . There are relays involved also ,but don't think there at fault . To be sure you need to do some electrical test to know for sure ! I suggest you take it to a ASE certified repair shop that has the knowledge , tools an service info - wiring diagrams etc.. ! Oh and a scan tool that can extract DTC'S from the BCM there could be a diagnostic trouble code pointing to the problem !
DTC B257A 00: Headlamp Switch Input Signal Mismatch
Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance
Headlamp Switch Off Signal
B257A 00
3
--
--
Park Lamp Switch On Signal
5
4
--
--
Headlamp Switch On Signal
B257A 00
2
--
--
Headlamp Ground
--
2, 3, 4
2
--

1. Headlamps Always On

2. Headlamps Inoperative From Switch

3. Unable To Turn OFF Automatic Headlamps

4. Park Lamps Inoperative From Switch

5. Park Lamps Always On
When the headlamp switch is in the OFF position, the body control module (BCM) receives a ground signal through the headlamp switch OFF circuit and an open signal on the park lamp ON circuit and headlamps ON circuit. When the headlamp switch is in the PARK or HEAD position, the BCM receives an open signal through the headlamp switch OFF circuit and a ground signal through the park lamp ON circuit or headlamp ON circuit.
Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Verify that a test lamp illuminates between the ground circuit terminal 8 and B+.
?‡'
If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Auto Hdlp. Disable Sw. parameter is Inactive.
?‡'
If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the BCM.

4. Verify the scan tool Headlamp Switch parameter is Inactive.
?‡'
If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.

5. Verify the scan tool Parklamp Switch parameter is Inactive.
?‡'
If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the BCM.

6. If all circuits test normal, test or replace the headlamp switch.

If the BCM needs to be replaced , it has to be programmed . The dealer is pretty much the only place to have that done at ! There are other places ,you have to look in the phone book or inquire at local repair shops . Some towns ,city's have mobile repair guy's that do flash programming of modules etc... Good luck hope I gave you some insight on the problem ! I tell people these thing's an it's like they don't believe me , I see they repost the same question . I started working as a Technician in 1984 at a Chevy dealer ship an have worked at Cadillac , Pontiac , GMC dealer ships ! I see all to often people trying to fix these type of problems by just replacing parts not knowing what they are doing an wasting there money an later bring it to the shop anyway ! So I hope you make a good decision an take to a qualified repair person or shop !

Remove the front bumper fascia upper bracket. Refer to Front Bumper Fascia Bracket Replacement .
1
Headlamp Screw (Qty: 2)
Notice: Refer to Fastener Notice in the Preface section.
Tip
Secure the headlamp fasteners in sequence, as indicated.
Tighten
3 N·m (27 lb in)
2
Headlamp Assembly
Procedure

1. <LI type=1>Pull forward on the outside edge of the headlamp in order to release the up and down locator tabs on the backside of the headlamp. <LI type=1>Pull forward on the top inside edge of the headlamp to release the inboard up/down locator. <LI type=1>Pull the headlamp assembly down. <LI type=1>Pull the headlamp assembly forward far enough to access the electrical connection. <LI type=1>Disconnect the headlamp electrical connector from the forward lamp harness connector. <LI type=1>Remove the headlamp assembly.
2. Aim the headlamps after installation. Refer to Headlamp Aiming .

this for aero headlamp, plastic lens. please rate.

SECTION 417-01: Exterior Lighting 1999 F-Super Duty 250-550 Workshop Manual
REMOVAL AND INSTALLATION Lamp Assembly —Headlamp, Aerodynamic Removal

1. NOTE: Make sure that the headlamp switch and the ignition switch are in the OFF position.
   Remove the headlamp assembly.
   1. Pull up and remove the two upper headlamp clips.
   1. Release the lower headlamp clip.
   1. Position the headlamp so the connector can be accessed.
   1. Disconnect the headlamp connector.

Installation

1. Install the headlamp assembly.
   1. Position the headlamp assembly.
   1. Connect the headlamp connector.
   1. Install the lower headlamp clip.
   1. Install the two upper headlamp clips.
      • If necessary, adjust the headlamps. For additional information, refer to Headlamp Adjustment—Photometric Aiming or Headlamp Adjustment—Screen Method Aiming in this section.
      

1. Check that headlamp switch (11654) is in the off position.
   
2. Lift hood (16612).
   
3. Release latch and swing filler panel to left or right.
   
4. Remove electrical connector from headlamp bulb by grasping wires firmly and snapping connector rearward.
   
5. Remove headlamp bulb retainer (13N019) by rotating counterclockwise (when viewed from rear) about one-eighth turn and sliding ring off plastic base. Keep headlamp bulb retainer as it may be used again to retain new headlamp bulb.
   
6. Carefully remove headlamp bulb from socket by gently pulling straight backward out of socket. Do not rotate headlamp bulb during removal.

Headlamp Assembly, Explorer
Removal and Installation

1. Disconnect battery negative cable.
   
2. Remove blind rivets (2) attaching screws (4) and radiator upper sight shield.
   
3. Remove turn/park lamp attaching screws (2) and pull assembly away from body. Remove bulb sockets from housing and remove lamp assembly. Repeat on opposite side of vehicle.
   
4. With turn/park lamp assembly removed, screw attaching grille to front fender flange is accessible. Remove grille attaching screw. Repeat on opposite side of vehicle.
   
5. Remove attaching screws (4) located across top of grille.
   
6. Grip lower edge of grille and pull outward to disengage from retaining clips. Remove grille.
   
7. Using needle-nose pliers, compress barbs on headlamp housing retainer. With barbs compressed, pull forward on housing just enough to disengage from retainer. Repeat on opposite side of headlamp housing.
   
8. Turn headlamp housing as necessary and pull forward to disengage from headlamp aiming ball socket.
   
9. Disconnect wiring from headlamp bulb socket.
   
10. If replacing headlamp housing, remove retaining collar and bulb.
    

For installation, follow removal procedures in reverse order. Make sure to check headlamp aim.

SECTION 417-01: Exterior Lighting 2001 Villager Workshop Manual REMOVAL AND INSTALLATION Bulb —Headlamp Removal

1. WARNING: The halogen bulb contains gas under pressure. The bulb may shatter if the glass envelope is scratched or if the bulb is dropped. Handle the bulb only by its base. Grasp the bulb only by its base. Avoid touching the glass envelope.
   NOTE: The headlamp bulb should not be removed from the headlamp until just before a replacement bulb is installed. Removing the bulb for an extended period of time may affect headlamp bulb performance. Contaminants may enter the headlamp where they can settle on the lens and reflector. Never turn on the headlamps with the bulb removed from the headlamp.
   NOTE: Make sure that the headlamp switch and the ignition switch are in the OFF position.
   Remove the headlamp bulb.
   1. Disconnect the electrical connector.
   1. Remove the headlamp bulb retainer by rotating it counterclockwise about one-eighth of a turn.
   1. Remove the headlamp bulb.

Installation

1. Install the headlamp bulb.
   1. Install the headlamp bulb.
   1. Install the headlamp bulb retainer by rotating it clockwise about one-eighth of a turn.
   1. Connect the electrical connector.

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go here for villager help

http://autos.groups.yahoo.com/group/villagerquest/

Nope! Here is the steps and a pic:


Headlamp Removal & Installation To Remove:

1. Turn headlamp switch OFF

1. Remove retaining ring screws.
2. Remove retaining ring from headlamp.
3. Remove headlamp from headlamp mounting bracket.
4. Disconnect electrical connector from headlamp.

To Install:

1. Connect electrical connector to headlamp.
2. Install headlamp to headlamp mounting bracket.
3. Install retaining ring to headlamp and install screws.