Xenon - blinking no more
Hi, since new (2007) my 159 have had the problem of the xenon/HID light having a life of their own going on and off. One unit at the time or both, and blinking or shutting off altogether. Since the controller starts them with extra high voltage to get them burning bright fast from startup, it looks as if I am flashing the high beam like a maniac...
I live in Norway where we have to use lights during day time driving. That way the problem is visible at all time. And the initial problem solving has been to clean the earth on both sides of the engine bay. And putting silicone grease on the connector on the back of the headlight unit. But that has proven itself not to be a cure.
In recent days the blitzing/blinking was just too much, coming home from a long drive with no lights on either unit. It was daylight but could have been a ticket. So the spanners are out.
The ECU sends the "light on" signal to the left unit and from their the right unit gets its signal feed. And since the problem has been independant of side I guess the ECU is not at fault. So the problem should be from connections to the unit or between unit and controller and bulb.
The spoiler off, headlight units unscrewed and on the workbench. I took off the controllers at the bottom of the headlight units and cleaned the contacts of controller to headlight unit, and opened the controller to make sure there were no obvious fault. Just greased the seal and refitted. They looked clean and no dust or water seemed to have been the cause, but at this stage, just clean all contacts although they look ok.
Took out the Xenon bulb and cleaned the contact to the bulb as well as the shielding on the wiring loom between the controller to the bulb contacts areas. Once again no obvious sign of a contact problem there either. But perhaps a bit loose contact flanges.
Cleaned the contact from the ECU to the left headlight unit, as well as the contacts to each unit.
Refitted the whole thing and on with the spoiler.
Two days of driving and all is well. So far...
No obvious faults, but a thorough cleaning of all contact areas might have done the trick.
I am sorry not to have one single or easy fix for all of you with a Xenon problem. A comfort might be that all other owner forums of xenon fitted cars are full of the same blitz problem so we are once again not left with a typical Alfa error. Just as annoying though...