I have a 1999-C5 coupe. the issue is that when i open the door the dash lights come on but when i turn on the headlights, the headlights pop up and come on. At the same time the dash lights go out and the tailights will not come on. By the way the brake lights do work. Any help would be great. Thank you.

 

Is your car totally stock or has the wiring been altered with aftermarket parts?

Pull your codes and post them.

 

I'm thinking maybe it's the headlight switch.

Someone else may have instructions on how to clean it.

 

As far as i know the car is stock. How do i pull my codes?

 

Would the headlights still work if the switch was bad? How do i check to see if it is the switch?

 

How to Pull Codes:
1. Turn your key to the "ON" position, but do not start the engine.
2. Clear any present messages by pressing the RESET button.
3. Hold the OPTIONS button down, and press the FUEL button 4 times. (This will get you into the "codes" section of the DIC.
4. The computer will automatically display all the codes your car has created. It will cycle through each code every 3 seconds. (Have a pen and paper handy to write down the codes)

Note: Any code that ends in an "H" is a history code (something that has occurred in the past, but is not reporting as an error currently.)

5. Once the computer has finished going through all of its codes, press RESET to enter Manual Configuration mode. It should start with a module and show "NO CODES" or "# Codes."
6. To optionally reset codes once in manual mode, press and hold RESET until is displays "NO CODES."
7. Press OPTIONS to go into the next module (ie, from PCM, or Powertrain Control Module, to TCS, or Traction Control System.)
8. Repeat Step 6 until you have reset all the codes in all the computer modules.

Note: Only reset the codes if you want to- it is not necessary to reset them every time you pull the codes.

9. When finished, simply take your key out of the ignition.

How to Interpret Codes
Now, once you've pulled the codes (it will usually be a letter followed by four numbers), you can go to THIS SITE to get an interpretation of what they mean.
http://www.stengel.net/diccodes.htm

 

I would suspect the MFS (multifunction switch) to be the culprit. It is unlikely that it would throw any codes. It is likely that the contact for the parking lights in the headlight on position is no longer working properly. You can attempt to disassemble and repair it, or do what most people do and just replace it.

 

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