1998 Mercury Grand Marquis Logo
Anonymous Posted on Jan 19, 2012

Headlight relay when in automatic and high beam, the entire lighing system goes crazy and then shuts off. I have to manually switch all lights off - only for seconds - and then back on and everything works fine as long as I do not use the high beam. Any solution?

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Michael Boutwell

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  • Contributor 111 Answers
  • Posted on Jan 19, 2012
Michael Boutwell
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I had an 05 Grand Cherokee that uses to almost strobe sometimes! I fixed that by cleaning the sensor. Its no cost and worth a shot! Good luck!

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Anonymous

  • 1586 Answers
  • Posted on Aug 30, 2008

SOURCE: Headlights do not work

I know it's a completely different make, but on my Audi (and on a few other cars that I've seen), that is a symptom of a failed headlight switch. You may simply need to replace it with a new one (or one from a salvage yard). They're usually not terribly expensive nor all that difficult to install, and if you have some basic tools and a little mechanical know-how you'll probably be able to swap it in your driveway without much trouble at all.

I can't promise that Mercury is the same as the other cars I've seen like this, but many cars that I've seen (from German to American to Japanese) all end up needing a new light switch when this kind of problem happens.

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0helpful
1answer

2006 hummer h3 headlights wont turn off!

Ive changed the relay and the headlight switch on the dash .. still wont turn off headlights ? Just changing parts won't fix it , need to test . Hooking up a professional scan tool , one that can read codes in the BCM - body control module is the way to start to find the problem . Then familiarize yourself with how they work.

Headlamps
Major components of this system are the body control module (BCM), headlamp relay, beam select relay, ambient light sensor, headlamp and panel dimmer switch, turn signal/multifunction switch, park brake switch, and the low and high beam headlamps.
The headlamps may be turned ON in 2 different ways. First, when the driver places the headlamp switch in the ON position, normal operation occurs. Second, when the headlamp switch is placed in the AUTO position, automatic lamp control (ALC) operation occurs. During ALC control, the headlamps will be OFF in daylight conditions or in low/high beam operation in low light conditions.
The headlamp relay receives battery positive voltage directly from the battery. The BCM supplies a ground signal to the headlamp relay for normal headlight operation. The BCM also supplies voltage to the beam select relay coil for high beam headlight operation. When the driver places the headlamp switch in the ON position and the dimmer switch is in the low beam position, the headlamp relay supplies current flow through the left and right low beam headlamp fuses to both low and high beam headlamps. Both low beam headlights are grounded through the beam select relay. When activated, the dimmer switch sends a ground signal to the BCM in the high beam position and a momentary ground signal in the flash-to-pass (FTP) position from G106. The BCM then energizes the beam select relay which switches the headlamp grounds from the low beam headlight bulbs to the high beam headlight bulbs illuminating the high beam headlights. With the headlights in the low beam position, the high beams may be momentarily turned ON or flashed by activating the FTP portion of the switch.
The instrument panel cluster (IPC) illuminates the high beam indicator when the BCM detects that the high beams are requested. The IPC receives a class 2 message from the BCM requesting illumination.
The Headlamps On at Exit and Perimeter Lighting modes can be adjusted using the steering wheel controls to select the function as displayed in the driver information center (DIC). The Headlamps On at Exit selection will allow the driver to customize the period of time that the headlamps remain illuminated upon exiting the vehicle. This period can be adjusted from 0-180 seconds. The Perimeter Lighting feature allows the driver to select if they want the headlamps and backup lamps to illuminate when the door UNLOCK button on the key fob is activated. This feature can be turned ON or OFF by using the DIC steering wheel control buttons.

DTC B2575 Headlamp Control Circuit

Circuit Description
When the body control module (BCM) senses a request for headlamp or daytime running lamp (DRL) illumination, the BCM sends a ground signal to the headlamp relay through the low beam headlamp relay control circuit. The headlamp relay will illuminate the low beam headlamps.

Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, command the headlamps ON and OFF.
Does the headlamp relay turn ON and OFF with each command?

Do you know what bi-directional control means ? Need a professional scan tool to do these type of test .

DTC B2602: Daytime Running Lamp Control Circuit Low or Open
DTC B2603: Daytime Running Lamp Control Circuit High

Without this type of info. from service repair manual an using a scan tool your missing the big picture .
0helpful
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Why don't lights work?

Both the headlight switch and the BCM provide a ground, or control circuit, to the headlight relay coil circuit for manual or automatic headlamp operation. When you place the headlamp switch in the OFF position, and the ambient light sensor indicates low light conditions, the BCM energizes the headlamp relay for low beam operation. You may switch the headlights to high beam by pulling the dimmer switch handle toward you until the dimmer switch is activated. When the dimmer switch is placed in the HIGH position, the indicator lamp input to the BCM is pulled low. The BCM then sends a class 2 message to the instrument cluster in order to illuminate the high beam indicator lamp.
Low and High Beams Headlamps Inoperative ?
Replace the headlamp switch. Refer to Headlamp Switch Replacement .
Did you check the headlamp relay ? Location ,left instrument panel
Did
0helpful
1answer

Where is the low beam relay switch located

Replace any blown fuses, and check or replace the head light relay.
0helpful
2answers

Where is the headlight low beam relay switch located on my car?

Look in the owners manual. Most like under hood on top of fire wall fuse and high amp. Relays under cover.
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My 2002 impala headlights don't work at night or in dark places like a tunnel or under a bridge, they only work in the day time. I have day time runner lights and they automatically turn on when I start my...

You can't turn them on manually with the switch . You have the switch set on auto ?
Headlamps
You can use the headlamps in two different ways.
• Place the headlamp switch in the ON position for normal operation.
• Place the headlamp switch in the OFF position for automatic lamp control (ALC). During ALC the high beam headlamps are On at reduced intensity for daytime running lamp (DRL) operation in daylight conditions, or low beam headlamps On in low light conditions.
The DRL/EXT LTS fuse and the EXT lamps fuse in the underhood junction block supply battery positive voltage at all times to both of low beam lamps and to the right high beam lamp. The low beam circuit continues to the high/low beam switch, then, depending on the position of the dimmer switch, connects to the normally-open headlamp relay switch contacts. Placing the headlamp switch in the HEAD position provides a ground path for the headlamp switch input of the Body Control Module (BCM). After receiving this input, the BCM energizes the headlamp relay. When the headlamp relay is energized, the low beam circuit is connected to ground G201. The high beam circuit is divided into a left and a right side circuit.
The DRL/EXT LTS fuse in the underhood ignition block supplies battery positive voltage to both the coil and to the normally-closed contact of the DRL relay switch circuit. During high beam operation, the left side current flow is through the closed contacts of the DRL relay, and to the left high beam lamp.
The EXT Lamps fuse in the top of the engine fuse block supplies battery positive voltage to the right high beam lamp. Both high beam circuits are then connected together, and continue to the dimmer switch. When the driver closes the high beam contacts of the dimmer switch, the circuit is grounded at G201.
Both the headlight switch and the BCM provide a ground, or control circuit, to the headlight relay coil circuit for manual or automatic headlamp operation. When you place the headlamp switch in the OFF position, and the ambient light sensor indicates low light conditions, the BCM energizes the headlamp relay for low beam operation. You may switch the headlights to high beam by pulling the dimmer switch handle toward you until the dimmer switch is activated. When the dimmer switch is placed in the HIGH position, the indicator lamp input to the BCM is pulled low. The BCM then sends a class 2 message to the instrument cluster in order to illuminate the high beam indicator lamp.
If the headlamp switch is left in the head position, the inadvertent power control feature will turn off the headlights 10 minutes after you turn the ignition switch to the OFF position. If you place the headlamp switch in the head 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 you turn them OFF or until the battery runs dead.
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Replace headlight relays 1999 lexus rx300

Moe likely a bad earth for one of the lights as one light is working through another causing one to stop working
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Daytime Running Lights Inoperative 2002 Toyota Camry

[Information] For a 2002 Toyota Camry, the Daytime Running Lights (DRL) operate utilizing the High Beams (inner Lamps closer to the center of the vehicle front) at a reduced power.

[The troubleshooting process:] Review the Owner's Manual and ensure the test configuration matches the following criteria:
1. According to the 2002 Toyota Camry Owner's Manual (Check your Owners Manual):
"The DRL system will make your headlights come on at a reduced brightness when:
The light switch s in the "DRL" position.
The ignition is on with the engine running.
The headlight switch is off.
The parking brake is released."


2. Set the Test Conditions according to Step 1 above.

3. Check the headlight bulbs to ensure they are not burned out. If one burns out, there is a fair chance that the other would have burned out at the same time. Replace as necessary. In this case, if the high beams operate, the DRLs should also operate.
4. Test the system, ensuring the step 1 conditions are set. (Engine running, Multi-function Switch on Turn Signals in "DRL" position, headlight switch off (repeating what the manual says -- it should be obvious that in the "DRL" position, the headlight switch should be off / do not have the switch positioned to "High Beam"), and the Parking Brake "off").
5. If DRL lights do not work, check the engine compartment Fuse and Relay Box. there is a 5 Amp DRL fuse -- replace it with the spare. Test (step 4).
6. If it does not work, swap around or replace relays -- there are three (3). Any one of them could be bad (stuck or burned out). Test (step 4).
7. Other less likely possible issues could be that the Multi-function Switch is broken or a connection / wire is broken. [Beyond the scope of this process.]


My problem was that the test configuration did not have the engine running and parking brake off - Step 1. Problem solved with much thought, repetitive tests on the vehicle and going back to the basics -- what does the Owner's Manual say and where are the applicable fuses and relays located?

0helpful
1answer

When I click the headlights to bright all of the lights go out. I have already replaced the switch in the stearing column. What is wrong.

Try disconnecting one of your headlights and click on the high beams. If it goes to high without any other problems, then the problem is in the other headlight high beam circuit. If all the lights go out, then the problem lies in the high beam circuit of the headlight you disconnected. You can verify this by reconnecting the first headlight and disconnecting the other one. There is most likely a short to ground in one of the high beam circuits.

If you have daytime running lights. That is, your headlights stay on automatically. You will need to check the daytime running light relays. There may be four of them to check. One of them grounds the high beams.
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High beams work but not the low beam lights

check relay!!!!!!!!!!!!!under hood in relay//fuse cluster,cheers
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ya know it kinda sounds like the headlight switch that switches from high beam to low beam has a bad contact. You don't have one of those 4-beam modules that turn on all 4 lights on high beam do you? that thing screwed my whole headlight system up, I ended up throwing it in the trash.

I have the chiltons and haynes manual, I'm sure between the two we'll find a good diagram. I gotta get my youngin to open house at school, but I'll pull the books out and send you the wiring diagram.
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