I have a 2001 volkswagen gti, and the headlights won't turn on as well as the heater& the directionals. I don't have a clue what it could be.

You should have a broken door switch.
Be blessed.

You have one before the catalytic converter and one after. They look similar to a short spark plug with a single wire protruding from the end, and are threaded directly into the exhaust pipe.

Check ground leads behind headlamps. Usually brown wires coming off headlight connectors.

1993-2005 Volkswagen Jetta, Golf, GTI, Cabrio (A3-A4) Hatchback & Sedan Workshop Repair Service Manual - 350MB PDF

1993 2005 Volkswagen Jetta Golf GTI Cabrio A3 A4 Hatchback Sedan...

This is a COMPLETE Service and Repair Manual for your 1993 1994 1955 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 VW Jetta, Golf, GTI, Cabrio (1.8L turbo, 1.9L TDI and PD diesel 2.0L gasoline, 2.8 LVR6) (A3, A4 Platform) Hatchback & Sedan. It covers every single detail. All models, and all engines are included.

This QUALITY manual is 100 percents COMPLETE and INTACT, no MISSING/CORRUPT pages/sections to freak you out! Detailed illustrations, exploded diagrams, drawings and photos guide you through every service repair procedure. This manual can be viewed on any computer, as well as zoomed and printed. All repair procedures are covered A-Z. This manual for VW Jetta, Golf, GTI, Cabrio makes any repair job easy to do with very easy to follow step-by-step instructions & pictures on all areas of repair.

1993 1994 1955 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 VW Jetta, Golf, GTI, Cabrio (1.8L turbo, 1.9L TDI and PD diesel 2.0L gasoline, 2.8 LVR6) (A3, A4 Platform) Hatchback & Sedan
===========
Format: PDF
System: All Versions of Windows, Mac, iOS, BB, Android, etc..
Requirements: PDF Reader.
Printable: Yes

TABLE OF CONTENT (example)

GENERAL INFORMATION *

ENGINE *
engine mechanical
engine lubrication system
engine cooling system
engine control system
fuel system
exhaust system

TRANSMISSION/TRANSAXLE *
clutch
manual transaxle
automatic transaxle

DRIVELINE/AXLE *
front axle
rear axle

SUSPENSION *
front suspension
rear suspension
road wheels & tyres

BRAKES *
brake system
parking brake system
brake control system

STEERING *
power steering system
steering system

RESTRAINTS *
seat belts
supplemental restraint system (srs)

BODY *
body, lock & security system
glasses, window system & mirrors
roof
exterior & Interior
Instrumental panel
seat

AIR CONDITIONER *
air conditioner system

ELECTRICAL *
wiring diagrams
starting & charging system
lighting system
driver information system
wiper, washer & horn
body control system
lan system
audio visual, navigation & telephone system
auto cruise control system
power supply, ground & circuit elements

MAINTENANCE *
maintenance

INDEX *
alphabetical Index

1993 1994 1955 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 VW Jetta, Golf, GTI, Cabrio (1.8L turbo, 1.9L TDI and PD diesel 2.0L gasoline, 2.8 LVR6) (A3, A4 Platform) Hatchback & Sedan

If high beams are working and the dipped lights not it is usually the headlight switch that is faulty and will need to be replaced.

There is four wires-two of them is white for the heater and another two is grey and black for the sensor.Zirconia or titania doesn.t matter.

My VW Golf gti. I have just had a service and my sevice light come on when i turn on the ignition, can you tell me how to turn it off please

Green/blue to negative side of the coil, yellow to the positive side of the coil.

The wiring is different, if your Golf had headlights with H4 bulbs then changing to high beam turns dip off. The GTi has separate dip and high lights, on high beam dip stays on (all 4 bulbs on).

have u tried jump starting as battery may show enough volts but not have enough amps