Bulb Failure......but no bulb failed ???

[GregE240]

Hi,

Happy New Year to you all !

I've got a slight problem on my 1998 E240 Avantgarde. When I have the headlights on and switch on main beam, after a second or so the "LAMP DEFECTIVE" sign appears in the little screen in the speedometer. Looking at the front lights last night, it appears that both main beam units are working correctly, and the blue light appears on the instrument cluster when the main beam is activated.

The only thing that I can think of is that both main light units should also light up on main beam, but currently are not. If this is the case, then both bulbs (or a fuse/both fuses) are blown. If it is fuses, are they under the bonnet, or in the side of the instrument cluster, or near the battery ?

Ideas anyone ? Its not due a service for about 3 months or so, and I don't want to take it in when it would appear that both main beam units are working okay.

Many thanks in advance.

 

[altreed]

Mine had a similar problem, check lamps are the same wattage

My c36 blew a lamp, I replaced it (on holiday) and could only get a different wattage, the warning came on.

 

[Keithm]

hi,

the lamp warning light will come on if any of the lamps are defective. Most likely ones are the brake lights but try reversing and indicators.

Oddly I had a warning just BEFORE a brake light went !!!! I got a freind to check all was OK but was still getting the warning - 2 days later the lamp failed.

Incidently the rear bulbs are not standard size ( what is these days !) so take the old one in with you when you get a replacement.

cheers

 

[waggers]

check your rear side lights too. There are two in the rear clusters...the outer one a standard 5w and the inner one a stop/tail 21/5...my lamp defective came on late one night then went out and came on again about a month later when the bulb eventually failed....

 

[PaulC]

My lamp out indicator would illuminate intermittently because the lamp holder was making a loose connection with a headlamp. A little pressure with a pliers on the metal connection solved the problem.

 

[Dringo]

My SL320 had the failure light on also and I couldn't see the problem...looking closer turned out to be a dead rear number plate illumination bulb! There are 2 and one was out.

Since you say yours only comes on when you select full lights (not side lights) I don't think this is your problem. Sounds like maybe one of your main bulbs in the front is 'about' to go, and the wattage detection is pretty sensitive.

Provided you feel you can see OK, wait until the service.

-jd

 

[mbzslk230k]

The other possibility is a damaged lamp control unit which all lamps are connected - costs a cool £100 to replace ! (just like a big relay!)

 

[GregE240]

I think it may be the unit actually. I ordered some Philips Vision Plus and fitted them yesterday.Still get Lamp Defective when Full Beam's on

Oh well. It can wait until the next service.