Newcommer needs help
 

Hi all, after many years as a jagman have finally come on board with a 1990 300 SE auto

I bought it yesterday and although in good nick have noted that NO panel instrmentation or switch lights are working. checked the main fuse box and evrything looks ok- cant beleive EVERY bulb has blown- anyone got any ideas where to look? is this a common problem?many thanks

instrument light failure
 

kay all the lights including gearshift window siwthc lights dash etc not o=working read posts pulled out dash, the rheostat IS operating teh centre temparture display so obviously the rheostat works- cant find this famous red fuse though

ok unit out (very easy) the rheostat IS dimming the bulbs but they just dont illuminate the dash so i'll get them all replaced- so does that mena i have to replace all the other buylbs in the gearshift window switches and any others i cant think of??

Verify bulbs are actually burned out before you replace them all. Hard to believe thay are all bad. I suppose overvoltage could do this but seems unlikely they are ALL bad. Where in the UK are you from?

Mike

thanks
 

hi from sheerness kent, the bulbs in the panel are ok but obviously dim- so can't understand why all the others are naff

Dash Lights
 

Try replacing the rheostat brightness control. Had same problem and though the dimmer was working, it didn't allow enough voltage through to light bulbs.Make sure that you're getting a full 12V out of the dimmer when it is wide open. Be careful not to short out anything when doing it! I had the same problem and this solved it. The other obvious culprit could be the ground connection which is usually supplied to the whole instrument cluster via a wire through the multi-pin connector, or separately. In American cars they usually are a brown wire to ground...can't say if yours is the same though. Also,check continuity from your ground wire to the surface ground of the cluster...if no continuity you know its the ground. Then try tightening all the outer nuts holding the cluster together. Good luck, Jeff

he must be
 

a brit to say "in fine nick". guessing.

tom w