My lights on the cluster went out all at once. The cluster still works except for the diagnostic, compass, and tach. Should I try replacing all the bulbs again(I did that when I replaced the original cluster), clean the contacts on the plug and spray it with dielectric grease, or just replace the cluster altogether?

I had a similar problem with my Buick. It turned out that the contacts the on the back of the cluster weren't making good contact with the metal tabs on the dash as the metal tabs were smushed down more than they should have been..

What I did was to pull the cluster, clean the contacts with alcohol and a rubber pencil eraser (both on the cluster and in the dash). Then, I took a small screwdriver and gently pried the tabs on the dash side of the contacts out so that they would press against the ribbon on the cluster better.

I put the dash back in and it worked again.

It could also be an open dimmer switch.

I'll take out the cluster and clean all that tonight, if it is the dimmer switch, just replace it?

Unless you want to try taking it apart to clean it as well.

Did you get this figured out yet?

Guys, I am having the same problem, took it to the dealer last week and they still can;t figure it out.