Weird problem!

My interior light comes on when opening the door, or turning on the key to the on position, fine.

However, neither of the map buttons turn on the lights or moving the slider doesn't turn on the lights!

The map button and opening the door, turn on the same lamp don't they? Any guesses to the problem?

 

Anyone with any ideas? its driving me mad!

 

Okay, i'm not an auto electrician but i'll have a guess.

Yes they are the same bulbs, so you know that is not the issue.

The bulbs are turned on when the switch, either door or otherwise, make a ground connection. Therefore you also know that you have a +12V supply to the lighting unit as this is a common feed.

Here is the key - the door switches and the actual light switches (the slider and the map buttons) use seperate grounds.

So my guess is that the ground within the lamp holder has lost its connection to the car body. Take off the lense cover, undo the to screws holding the housing to the body and investigate. Could just be a rusty conenction. I think its one of the screws itself that provides the ground.

 

Try swapping the cluster from someone elses car
The map button just changes the brightness IIRC

 

The brightness changes because the circuit to ground is much shorter when the map buttons are depressed - eg doesn't have to go via the door switches, IMO.

 

Will try this after work

thanks a lot

 

Will try this if the above doesnt work