ihaveaquestion

the right and left braking light bulbs are blown. The passenger side headlamp bulb is blown too. Normally I would replace them without a question.

However, I found that when the engine is shut off, both headlamps stay on for 30 seconds before auto shut off. I mean...aren't these the same low beam bulbs as when the car is moving? When wouldn't it turn on when the car is moving but only turn on when the engine is shut off?

If they are the same bulbs I suspect there is something electronically wrong with my car and that's why I am hesitant to replace the braking light bulbs as well.

Does anyone know if W202 uses the same headlamp bulbs for low beam and parking (before auto shut off)? Thanks a million!

ihaveaquestion

Now, I am pretty certain there is something wrong with the car. The new bulbs were installed for the stop lamps just this weekend...they are both blown today...just 3 days later. I can hear a hissing noise at the back of the car but not able to locate the source of the sound. I am thinking maybe the fuse has an issue. Can someone help?

ptcruiser

Best step to begin with is to remove the printed circuit board where the rear bulbs are located, and check for corrosion.
You can try to clean with contact cleaner and use a small screwdriver and soft cloth to rub in the sockets to get any grime and rust out.
This worked for me for the brake lights
Head light, I have NO idea

ptcruiser

The hissing sound is the air pump. Quite normal.

ihaveaquestion

By air pump, do you mean fuel pump by the fuel tank? I know the initiation stage makes noise but constant noise afterward?

My instinct just tells me the hissing sound is coming from some electrical component...

I read about OVP (over voltage protector)...sounds like a part that fails with regularity. Can someone elaborate on this? I watched a youtube video showing how to fix with soldering. Think of it, my dashboard (the numeric digit doesn't display correctly) and radio don't always function properly...there just seems to have some kind of electrical issue on my 2000 W202.

ptcruiser

There is an air pump that activates from the trunk. It works the vacuum for the door locks, trunk lid etc. It's on the right side looking into the trunk behind the right side trunk liner. You need to remove some black plastic clips to get at it. Possibly a vacuum leak.
They can run for several seconds, but not constant. If you want to check it, there are several plastic tube lines attached to the pump. Take each off individually and hold your finger over each nipple of the pump and see if the pump stops running.

mickey13

ever solve this? sounds like a bad ground.

ihaveaquestion

sort of but not really.

So I cleaned up the circuit board as someone suggested above and it works better now. I sitll have bulb warning light coming on and off, I suspect it's a contact issue with the circuit board. The best solution may be to replace the rear lamp circuit board.

mickey13

rear lamp circuit board? is that the board that you actually screw the bulb into? i have a similar issue with a parking light that went out on me, but i replaced that board the bulbs go into and no go. (btw, which side are you looking for, i still have the new one i bought in the box i think)

maybe for yours, you can also try some dielectric bulb grease. on mine there doesnt seem to be any juice coming into the harness (i tested it with a multi-meter) so i'm guessing mine is a bad ground or it could be a bad headlight switch (hoping it isnt a bad harness). just wondering aside from:
1. the ground on the battery,
2. the engine ground,
3. the ground under the headlight,
4.and the ground up on the left side under the hood,,,,

are there any more grounds?

shadenfroh

Rear license plate lights are a common cause for occasional warnings. Even if they do in fact work, the contact points degrade over the years. Replace them for sake of sanity and keep the old ones as spares for the cabin lights which I think are not monitored.

mickey13

when you say rear license plate, do you mean the bulbs or the fixtures.





FYI anyone looking to replace their license plate bulbs, its dopne by taking off the carpet from the inside, not by unscrewing the screws by the lights which although seems more natural is not the right way to do it. the center bolt on the outside will not come off.

shadenfroh

The bulbs themself. The fixtures rarely need replacing unless the car has been super neglected. Just clean them up.

Sorry I forgot to mention how you replace them, I hope you knew that beforehand!

mickey13

i learned the hard way last week before this post LOL.

funny though one of my rear license plate bulbs was out. have no idea if it threw an error because i have the error from the rear passenger tail (parking light).

i just replaced the trunk dome as well, last owner had cracked the lens somehow and it fell apart on me when i did my interior LED conversion. interestingly enough the trunk lens comes with a bulb. swapped it out with my LED and back in business. i think and im not sure, i need to really pay attention but i think when the trunk bulbis out you will get an error on your trunk release switch. i noticed it started staying lit after that light was disconnect while i was waiting for the replacement lens.

shadenfroh

Yes, the licence plate bulbs are monitored. I just had one mess with my head for two months!

I'll try the trunk release thing later today.