2003 Xenon (Litronic) Headlights problem

[targa rouge]

Hi.

My Porsche Targa Xenon (Litronic) headlights low and high beam (both sides) do not energize when install on the fenders bay.

Both assemblies were removed and energized using an external 12v battery connected as follows:

-for high beam: headlight assembly port 4 (+ve batt terminal) and port 6 (-ve batt terminal) [** the wiring diagram shows the port 12 as -ve but on the headlight assemblies were connected on port 6].

-for low beam: headlight assembly port 11 (+ve batt terminal) and assembly port 12 (-ve batt terminal).

Voltages, fuses, ground and cables continuity were checked. Voltage at the headlight fender connectors were 12.5 volt at

Low beam: port 11 as +ve and port 12 as -ve.

High beam: port 4 as +ve and port 6 as -ve.

The assemblies were connected (off the fender bay - were not installed). As soon as the +ve cable was connected from the fender connnector (using a jumper) to the port 4 on the assembly a drop on voltage occurs as if as ground as present. This did not happen when the assemblies were connected to the external 12v battery.

Any ideas?

[Richard Hamilton]

I assume it is the same on both sides. The main headlight switches are a known problem area, so maybe there is a bad (high resistance) contact inside. Just a thought.

[targa rouge]

Hello.

Yes on both sides.

Are you refering to the main light switch or the low/ high switch at the steering column?

Is possible to have good voltage at the fuse +ve to ground (without the fuse install) and good voltage at the fender connector to ground (with the fuse install) and no voltage when the assembly is connected?

I'm discarding the headlights assemblies because both energize all bulb with th external 12v battery connected directly to the port on the assemblies connectors.

[Loren]

The main headlight switch is the known failure point.

You will find several DIY replace threads here if you search.

[targa rouge]

THE HEADLIGHT SWITCH HAS TWO MAIN COMPONENTS;

PART NUMBER: 996.613.535.00 (LIGHT SWITCH)

PART NUMBER: 996.613.631.01 /LL (HEADLIGHT UNIT)

HOW DO I TEST EACH ONE TO DETERMINE THE DAMAGE COMPONENT?

[Loren]

The headlight unit (996.613.631.01) is just a positioning plate - nothing to test.

Usually a bad switch will act very erratic when switched back and forth rapidly.

Please do not post in ALL CAPS - as that is shouting on the Internet. No need to shout here.

[targa rouge]

Sorry. This was the way I write down all my e-mails. No "shouting", disrespect or anger were intended.

Thanks.

[targa rouge]

General knowledge:

The headlight main switch was removed from the dash.

The Part Number: LL/996.613.631.01 (Headlight Unit)

has an electric circuit with a 4 pins/cables connector attached to the unit.

[targa rouge]

The replacement light switch wass received and installed today. As both reported, the problem was the main switch.

Thanks.

[johnbruni]

in the DIY instructions it might be helpful to mention the secret screw buried inside the switch race. hard to see and know that it is there and you cant get the vent cover off without taking it out.

thanks

jb