I am working on a 99 Impreza and I want to eliminate the factory dash cluster and install a custom one. I have been told that the center diff lights and thumb wheel control wiring run through the cluster. Is this correct and can the change out be done with a minimum of re wiring?
Any help would be appreciated!
Thanks in advance.

By installing a custom one, do you mean simply replacing the cluster with aftermarket choices like Syms or Zero/Sports, or building your own cluster out of various gauges & displays?

If it is the former, afaik, they should have a proper harness to make the swap work with minimum modifications.

If it is the latter, I'm afraid you may have little luck here, as most members here are in north america, and we don't get Imprezas with DCCD until the WRX STi came almost 2 years ago. My guess is that the DCCD thumb wheel control connects to the dash cluster only to supply display signal, and thus the thumb wheel should still be able to operate. If not, you'd have to look at the wiring diagram from the factory service manual to see which pin on the thumb wheel connector needs to be connected to power and ground.