Instrument lights

[BuickGSrules]

Hope you guys can help. Suddenly all my lights in the instrument is gone? I have light in the heater control section, in my tach and shift lever in the console and in my aftermarket gauges that is connected to the instrument lights, and I can adjust the light strenght in anything unless the instrument. For some while ago I changed all the light bulbs and I have checked if some of the sockets had gone loose, I have checked that the connection cable with the wires is in place and pushed in.
Do any of you have a clue what could be wrong? Thanks.

Jan

[Brian]

Since all the other dash lights work, it is most likely something wrong with the plastic printed circuit sheet on the back of the instrument cluster.  My guess is that when you had it apart before, the copper de-laminated from one of the connections where the large connector plugs into the back of it.  You will need to remove the whole assembly from the car and examine it and I think you will find something wrong at or near that connection. 

[BuickGSrules]

When changing the bulbs I did not remove the big connection cable. After the lights disappeared I tried take it out and plug it back in for seeing if it was something with that. But yes I had thought the same thought that it might could be something with the thin plastic on the back. I assume if the connection is broken somewhere on that all the lights go out? Sort of like a christmas light chain, right?

[Brian]

All the lights work off of one wire in that big plug, and of course the ground (so I guess that makes 2 wires!).  If everything else works, but the lights don't, then it is probably the positive wire for the lights in that connection.  After the current makes it onto the plastic sheet circuit board, it branches off in different directions, so if the problem were on the sheet, it would not make them all go out unless it is broken right where it comes out of the connector.  i.e., the lights are all wired in parallel, not series like christmas tree lights. 

[BuickGSrules]

Thanks. I will pull the connection plug and measure the positive and see if there is any voltage there.