Originally Posted by pizzaguy

This has come up maybe five times in the sixteen years I've been an owner/forum member. No one EVER comes back to tell us what fixed it, or if they ever fixed it.
The problem appears to be in the instrument cluster, see the inaccurate and incomplete diagram from the service manual below. I close look tells us that the diagram is baloney, as it shows a 12 volt line tied directly to ground, so we KNOW this diagram is not accurate and must be used carefully.

The only time I heard of this being fixed was when one person went to a junkyard and pulled the instrument panel from another car and put it in HIS car. I beleive the entire issue is in that square box in the diagram, which represents the logic gate and current switch that turns on the lights which are powered from battery power.

Try pulling fuse 35, post here and tell us if that turns those lights off. If so, one thing you COULD do is install a small relay to disable that battery feed to the IC. That would probably be easier than replacing the IC.