I've had the 1999, 911 Cab for a short time and I'm trying to resolve each issue I encounter. The current problem involves the headlights, when the key is on and/or the car is running, the HD's are only about half or less as bright as they should be . . . they do not light the roadway. The brights do not come on except in flashing/manual mode. The dash light switch 'feels' a little sketchy, loose moving and doesn't click from one position to the other. The 1/2 bright HD's really has me puzzled . . . help! Larry

 

Headlight switch failure is common for the 996. I'd start there.

 

As Dennis stated, it sounds like it could be your Headlight switch. We can order you one if that's the case, for more information Click Here.

 

Also the connection between the lights themselves and the wiring harness can be sketchy. Not to mention some of the connections in/on the lights themselves. The lights are really easy to take out and it may be worth taking them out and spraying some electrical contact cleaner on the connectors.

 

you can clean your headlight switch with contact cleaner .