When i turn on headlights the engine shuts off

If the headlamps on your 2001 GMC Sierra won't turn off when the truck is started, there are a few potential causes for this issue:
1. Faulty headlight switch: The headlight switch may be malfunctioning, causing it to remain in the "on" position even when the truck is started. A faulty switch can prevent the headlamps from turning off as intended.
2. Stuck relay: There could be a stuck relay in the headlamp circuitry, keeping the power to the headlamps constantly engaged. A stuck relay can cause the headlamps to remain illuminated even when the switch is off.
3. Wiring issue: There may be a wiring problem, such as a short circuit or a damaged wire, that is causing a constant supply of power to the headlamps. This can prevent the headlamps from turning off when the truck is started.
4. Daytime running lights (DRL) malfunction: If your Sierra is equipped with daytime running lights, there could be a malfunction in the DRL system. This can cause the headlamps to stay on at all times, regardless of the switch position.
To address this issue, you can try the following steps:
1. Check the headlight switch: Inspect the headlight switch for any signs of damage or wear. If the switch appears to be faulty, it may need to be replaced.
2. Check the relays: Locate the relays associated with the headlamp circuit and check if any of them are stuck or not functioning correctly. If a relay is found to be faulty, it should be replaced.
3. Inspect the wiring: Thoroughly inspect the wiring harness and connectors in the headlamp circuit for any visible damage or loose connections. If any issues are found, the wiring should be repaired or replaced as necessary.
4. DRL system troubleshooting: If your Sierra has DRLs, consult the vehicle's owner manual or a service manual to understand the DRL system's operation. Follow the troubleshooting steps outlined in the manual to diagnose and resolve any issues with the DRL system.
If you're unable to identify or resolve the problem on your own, it is advisable to consult a qualified mechanic or take your GMC Sierra to a reputable auto repair shop for further diagnosis and repair.

Question edited for typos and English :>D

Google

year make model fuse box diagram

https://www.google.com/search?q=2001+chevy+tahoe+suburban+fuse+box+diagram

It could also be the switch. Or coincidental failure of both bulbs. Check with a test meter.
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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 .

One thing I want to mention all three of my vehicles will leave the light on after I shut the engine off, it is a security thing. My Chrysler 200 lights will stay on about 2 minutes.

https://www.youtube.com/watch?v=fjunXA5aRqU

https://www.lifewire.com/car-headlights-wont-turn-off-534834
From owners manual below page 5-102
Headlamps The headlamp wiring is protected by four fuses. An electrical overload will cause a lamp to go on and off. If this happens, have your headlamp wiring checked right away
https://my.buick.com/content/dam/gmownercenter/gmna/dynamic/manuals/2004/buick/rainier/2004_buick_rainier_owners.pdf

https://s17.postimg.org/fziahwj27/headlamps.jpg

Click on the link.
I don't know if this info will help? Can you operate the headlamps in the manual position, instead of auto position?
Do you want the wiring diagram?

Headlamps
The headlamps are operated when the driver places the headlamp switch in the HEADLAMP position. The LT HDLP and RT HDLP fuse in the IP fuse block, supply battery positive voltage to both the left and right headlamps. The low beam and high beam circuits continue to the headlamp switch. Depending on the position of the dimmer switch, either the low or high beam circuit will now have a path to ground. Ground is provided at G204. The low beam and high beam circuits also provide the body control module (BCM) with both low and high beam inputs. The headlamp switch includes the dimmer and the flash-to-pass switch.
If the headlight switch is left in the HEADLAMP position, the headlights will remain on until turned off or the battery runs dead.
Daytime Running Lamps (DRL)
Any function that turns on the headlights will cancel the daytime running lamps operation. The LT HDLP fuse in the IP fuse block supplies battery positive voltage to the daytime running lamp (DRL) relay coil circuit. The DRL relay switch contacts are connected to the low beam circuit. When the headlamp switch is placed in the OFF position, the BCM will turn on the daytime running lamps. The BCM energizes the DRL relay, closing the switch contacts and grounding the low beam circuit at G204. The DRL illuminate the low beam headlights at a reduced intensity. The DRL will operate when the ignition switch is in the RUN position, the gear selector is not in the PARK position and the parking brake is released. When these conditions have been met the DRL will illuminate.
DRL operation in Manual Transmission equipped vehicles will occur when the ignition switch is in the RUN position, and the parking brake is released.

Probably the dimmer switch . But without testing that would be just a guess . Turnning the headlamps on Any function that turns on the headlights will cancel the daytime running lamps operation..
No ,don't think the DRL relay has anything to do with it .

View wiring diagrams an testing the electrical circuits at the dimmer switch would be the proper way to diagnose .

I have a 1997 cadillac deville that has both 'daytime running lamps' when put into gear and 'twilight sentinel' which turns the headlamps and parking lamps on at night, and goes off during the day or when it is bright enough.

There is an adjustable delay for the twilight sentinel to turn the headlights off after the ignition key is removed and it is night time.
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I had the 'daytime running lamps' installed on a 1990 Cadillac Deville that turns the headlamps only on when the ignition key is switched to on with an aftermarket module. The headlamps are about 70% or so as bright as the regular twiilight sentinel headlamps and parking lights and are designed to go on during the day.

The twilight sentinel overrides this feature when it gets dark outside.

I had the daytime running lamps installed by an auto electric shop that specializes in electrical systems, alarms, stereos, etc.

Does this help?

must of this vehicles with automatic headlight systems, lights will shut down or turns off after few minutes giving driver time to walk to a secure place, is it possible lights won't turn off at all, you must have problem with headlamp delay system

replace the main headlight switch and the connector to that switch, the connector can be obtained from the dealer only in most cases.

manual headlamps

Visual Inspection Chart
Mechanical Electrical

• Headlamp switch
• Multifunction switch

• Central junction box (CJB) fuse:
  • 7 (30A)
  • 30 (15A)
  • 46 (10A)
  • 47 (10A)
• Circuitry
• Headlamp bulbs
• Daytime running lamp (DRL) relay No.1

Autolamps

Visual Inspection Chart Mechanical Electrical

• Headlamp switch

• Central junction box (CJB) fuses:
  • 19 (5A)
  • 56 (30A)
• Circuitry
• Headlamp bulb
• Daytime running lamps (DRL) full relay No.1 (if equipped)
• Vehicle security module
• Photocell

If autolamp system, Vehicle security module has a headlamp rela inside of it. under left side of dash.