Parts Catalog Accessories Catalog Tech Info Tech Forums
  Search our site:    
 Cart  | Project List | Order Status | Help    

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 12-06-2003, 03:05 PM
Registered User
Join Date: Dec 2003
Posts: 3
Xenon install - Bulb Inoperative Warning

Just installed aftermarket Xenon lights on a 99 E320 (W210). Lights are fine but am getting the 'Bulb Inoperative' warning message in the instrument cluster. Looked through thread and found the dealer can make adjustment in computer for xenon bulbs. 3 different dealers and no go because that functionality was not put in until 2000 and mine is a 99. Installed a 12volt 1 watt bulb on either side of the original headlight connectors hoping to trick the computer and that did not work either. Anyone have other ideas on how to resolve this issue?
Benjamin Jarrett
Reply With Quote
Old 12-06-2003, 11:16 PM
mike690003's Avatar
Registered User
Join Date: Apr 2003
Location: Miami,FL
Posts: 807
To break you the bad news:

The "Bulb out" light will most likely stay on because the Xenon light use 35 watts , while your old lights used 55 watts. The car thinks that a bulb is out because the Xenon lights use LESS power than the old lights.
1987 mercedes 300E
1995 e320 conversion(hated the 300e grill)
HID/Xenon (D2S)
Keyless Entry
Monochromatic Paint (Custom Blue)
Smoked Tails
Flat Badged (front)
Debadged (rear)
custom "carbon fiber" console
18 inch HP EVO rims
Sold! Now I drive a Monte Carlo SS

Reply With Quote
Old 12-07-2003, 05:40 AM
Registered User
Join Date: Sep 2002
Posts: 150
i assume that the system is wired so that the original wire for the light is used to power the xenon?

if so, you need to add a resistor in parallel with the current system, to lower the resistance to the 'right' level.

Power = Volts x Amps
old power = 55 = 12 x amps => 55/12 = 4.58 amps
new power = 35 watts = 12 x amps => 35/12 = 2.92 amps

so you need to loose 4.58 - 2.92 amps = 1.66 amps

1.66 x 12 = (roughly) 20 watts 12/1.66 = resistance = 7 ohms

so - you need a 7 ohm, 20 watt resistor (BIG!!!!) - or a 20 watt bulb across the power to bulb to ground connection.

IF the power to bulb is used just to power the 'black box' and the main power is taken from the battery, then you need to stick a bulb in between there and ground - try a 20 watt to start withj (im not sure quite how smart the syetm is)...


C140 420 CL
W114 280CE pimpmobile
W114 250/8 Hillclimber with M110 and bike carbs - got any hot cams?
Reply With Quote
Old 12-07-2003, 05:41 AM
afmcorp's Avatar
Registered User
Join Date: Jan 2002
Location: NW Indiana LaPorte
Posts: 571

well if that is the case then by going to a 100/80 bulb (jc whitney, ebay etc xenon headlight that should have just about the right draw wouldn't it? about 51 watts. for about 15 bucks you could try it out and if it worked you'd be using 80 watts and wouldn't need hi beam very often.

just a 2 cent thought
Thanks Much!

1972 350sl Red/Blk 117k
1988 420sel charcoal/Blk 140k
1987 420sel gold/tan 128k
See My Cars at:

Pound it to fit then Paint it to match!

There is only First Place and Varying degrees of last!

Old age and deceit will overcome Youth and Enthusiasm every time!

Putting the square peg in the round hole is not hard... IF you do it fast enough!

Old enough to know better but stupid enough to do it anyway!
Reply With Quote
Old 12-07-2003, 12:24 PM
benzfan's Avatar
Registered User
Join Date: May 2001
Location: Toronto
Posts: 277
Hop over to and check the threads there. This issue has been solved by the young enthusiasts with more free time than us old folks.
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 12:17 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page