IIRC there are only two grounds for the dash. Both are on the outer mounting pionts. There will be two 10mm headed bolts. One on the drivers side by the steering colomn area. There is a metal support that runs on the bottom edge of the dash. This is a self tapping bolt that threads into the metal support. The other is on the right side up by the ECM. Just look for the black wires with the eyelets. Also make sure the dash is screwed down tight on the bottom were it mounts to the body.
