00 Jetta 2.0 Car has daytime running lights but when switch is turned to on position car has no low or high beams. I can pull the turn signal lever and high beams come on but go off when released. I checked the voltage going to the headlight switch and it has power and the test light lights up with the switch is flipped. I was wondering if it is possibly a bad switch, dimmer switch, or relay

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 .

Hello. It seems your Chevrolet has either faulty headlamp relay(s) or its headlamps are connected in series; if one don't light, neither will the other one. I can't explain why the 'CHECK ENGINE' light was still on while your truck's engine was off and key was out of ignition switch. Good luck and keep me informed; if you want to.

Low Beam System Operation
The headlamps may be turned on two different ways. First, when the end of the of the turn signal/headlamp switch lever is turned to the second detent position, the headlamps will illuminate. A ground signal is provided to the DRL control module. The module then provides a ground path to the coils of the HLP relay. Since the head relay is provided with battery voltage to both the contacts and the coil, the coil becomes energized and closes the contacts providing voltage to the DIM relay. With voltage and ground provided, the low beam lamps light. Second, with the switch in the OFF position, for automatic lamp control (ALC). During ALC the headlamps will be in one of the following modes of operation:
• Daytime running lamp (DRL) operation in daylight conditions, refer to DRL below for the operation of the circuit.
• Low beam headlamp operation in low light conditions. When the ambient light sensor senses a low light condition for approximately 15 seconds, it will cancel DRL operation and turn on the headlamps at 100 percent intensity. A path to ground is provided to the coil of the HLP relay. With a direct path to ground provided to the headlamps though the DRL control module, the headlamps will light at 100 percent intensity.
High Beam System Operation
The high-beam headlamp operation is controlled using the turn signal/headlamp switch lever on the steering column. In order to change headlamp operation from low-beam to high-beam, push the switch lever toward the instrument panel (until the detent is felt) and release. With the switch lever in the high beam position, ground is provided to the DRL control module through the turn signal/headlamp switch and splice pack 200 to G200. The DRL control module provides a ground to the coil of the dimmer relay. Since voltage is being applied to the dimmer relay coil, it becomes energized. Voltage is then applied through the closed contacts of the dimmer relay and the to the high beam lamps in the headlamps. Since ground is provided to the headlamps through the closed contacts of the energized DIM relay, the high beam lamps light. The high-beam indicator (blue) in the instrument cluster will light during high-beam headlamp operation. In order to change headlamp operation back to low-beam operation, pull the turn signal switch lever toward the driver (until the detent is felt) and release.Your best bet , take it to a qualified repair shop.

It's probably the switch , but testing to know for sure is alwasy a good idea .

Headlamps Inoperative - High Beams
Step
Action
Value(s)
Yes
No
1
Did you perform the Daytime Running Lamps (DRL) System Check?
--
YES - Go to Step 2
NO - Go to Daytime Running Lights (DRL) System Check
2
Disconnect the turn/hazard headlamp switch connector C1.
Connect a fused jumper between terminal B of the turn/hazard headlamp switch assembly harness connector C1 and ground.
Do the high beam headlamps operate?
--
YES - Go to Step 3
NO - Go to Step 4
3
Replace the turn/hazard headlamp switch assembly.
Did you complete the repair?
--
Go to Daytime Running Lights (DRL) System Check
--
4
Repair the open in CKT 1200 between the turn/hazard headlamp switch assembly. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?

Daytime Running Lights (DRL) System Check
Step
Action
Normal Result(s)
Abnormal Result(s)*
1
Turn the headlamp switch to the HEAD position.
Turn the headlamp dimmer switch to the LOW position.
The low beam headlamps are ON.
The high beam headlamps are OFF.
Headlamps Inoperative - Low Beams
2
Turn the headlamp switch to the HIGH position.
The high beam headlamps are ON.
The high beam indicator is ON.
The low beam headlamps are OFF.
Headlamps Inoperative - High Beams
3
Turn the headlamp switch OFF.
Turn the ignition to ON.
Disengage the parking brake.
The high beam headlamps come ON at a reduced intensity in approximately 30 seconds.
Daytime Running Lamps (DRL) Inoperative, Headlamp Switch Operates Normally
* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.

No on the fuse . The LH HDLP and RH HDLP fuse in the fuse block - under hood, supply battery positive voltage to both low and high beam lamps at all times. For manual operation, when the headlamp switch is in the ON position, the headlamp switch supplies ground directly to the headlamps and to the body control module (BCM) on the headlamp low or high beam signal circuit, depending on the position of the headlamp dimmer switch. The BCM uses this signal to determine if the conditions are present to illuminate the daytime running lamps or park lamps.
The headlamps may be turned on 2 different ways. First, when the driver places the headlamp switch in the ON position, for manual operation. Second, with the headlamp switch placed in the OFF position activating automatic lamp control (ALC).For ALC operation, the BCM receives a signal from the ambient light sensor indicating a low or high ambient, outside, light level. Under low light conditions the BCM grounds the headlamp relay control circuit energizing the headlamp control relay. The now closed relay supplies ground through the headlamp switch to the headlamps and the BCM on the headlamp low or high beam signal circuit, depending on the position of the headlamp dimmer switch. When the BCM grounds the headlamp relay control circuit it also grounds the park lamp relay control circuit illuminating the park lamps. The headlamp relay is grounded at G203.
Daytime Running Lamps (DRL)
The low beam headlamps operate at reduced intensity when in daytime running lamps (DRL) mode. The ground circuit to the switch side of the DRL relay has a resistor in-line to reduce the intensity of the low beam headlamps for DRL operation. The body control module (BCM) receives a signal from the ambient light sensor indicating a low or high ambient, outside, light level. Under daylight conditions the BCM grounds the DRL relay control circuit energizing the DRL control relay. The now closed relay supplies ground directly to the low beam headlamps and to the BCM on the headlamp low beam signal circuit. The low beam headlamps now illuminate with reduced intensity. The DRL relay is grounded at G203. Any time the headlamps are illuminated the DRL will not illuminate. Manual park lamps do not effect DRL operation.

Daytime running Light module is overheating / it reduces power to low beam to create daytime running light . Ask yourself do I need this - If no law against it = UNPLUG control module . Your low beams will operate normal by turning on switch - Lever / Turn switch will turn on Highbeams but this switch can be Lose internally and Only cure is replace Signal Light Steering wheel switch . Common issue for all Cars is switch stalk / Lever is worn out by Aggressive use. If your car has Automatic light control - re they turn off after 30 second delay when you exit car - Try putting switch in manual mode means you Turn on - off by switch . But I really feel signal stalk is worn . DRCM is a known issue that can be unplugged . Final cheap solution unplug both high beams an Drive on low beam . $$$$$$$ spent chasing small problem will destroy $$$ needed for Bigger issues .

First, be sure that the headlights are actually coming on. These cars have daytime running lights that use the headlight bulbs at a lower voltage. If the car is only using the daytime running lights, the tail lights will not be on with the headlights. The multifunction lever always turns on the high beams when you pull on it (it's called 'flash to pass'). Make sure the headlight switch is working, and also check the headlight circuit breaker.

The problem is in the high beam switch assembly which also houses your turn signals and possibly cruise control, and yes, I'm sure. There are some electrical contacts in the assembly which dis-connect the low beams when you put the high beams on. Constant use of the high beam switch will create arcing on the low beam switch which makes the contacts not conduct electricity anymore. The daytime running lights send power to the low beams on a separate circuit. .

The repair is to either replace the assembly, $300 at dealer, $100 or less do it yourself, or take the assembly apart and clean it for free. (2 hours or less)

Instructions on taking your steering wheel off here: http://forums.tdiclub.com/showthread.php?t=151557

Instructions for fixing the switch here: http://forums.tdiclub.com/showthread.php?t=167831&page=4

P.S. If you own a VW, especially around model years 1999 to 2004, there is a rare but devastating problem with engine coolant being literally pumped through all electrical parts of your car.... destroying it. Repair cost = $8,000. It is called coolant migration. Check your VW right now (takes two seconds, literally), and do a two-minute procedure to fix your car to prevent the problem here: http://www.myturbodiesel.com/1000q/multi/coolant_migration.htm

https://s12.postimg.org/6o2zcv3hp/jetta_headlamps.jpg

Click on the link.
This is for 03 jetta gls
There are fuses for left and right low beams. Headlights on low beam, use a test light, see if voltage on fuse circuit? If no voltage that will lead us back to dimmer switch or problem with wiring circuit from dimmer switch.

pull on the signal lever toward you (ceter position). the signal lever controls the head lights either high beam or low beam. if you pull on the signal lever toward you again, you will have high beam temporarily. and if you push the signal lever towards the front, you will have the high beam locked.