My son is considering an '89 Deville Fleetwood, his dealership traded it for $100 and it's in great shape. The only thing that worries him is the digital dash, climate control and fuel displays do not light up. He is a mechanic and can do his own work but if the parts, etc. to fix these issues are too much, he will probably pass on the car. Can anyone help him with an idea of how costly these repairs might be? Also, anything to look in these years/models for would be helpfull.
Thanks,
Bill

Its most likely the BCM (body control module) as the power supply for those displays is internal to that module. Very common part, should be able to find one in a junkyard without too much difficulty.

Check for broken or loose wires first.