Replaced A/C module fix LCDs, now lost dashboard!
 

I double checked the connectors and even put the old module back in. The dashboard used to work with the old module but no longer does. I must have screwed up something in the replacement process. Has anybody else had this experience and what's the fix? Thanks, Tom
No speedo, no tach, no gas readout, only the turn signal arrows work.

That definitely sounds odd. I cannot say for sure what is causing your problem, but here are some trouble-shooting tips. You may have thought of them already.

Did you disconnect the battery when you replaced the AC module? If you didn't, it is possible that something shorted. In that case consider checking your fuses.

Another possibility is that the ignition switch chose this opportunity to fail.

You could also try re-seating the three connectors on the back of the instrument cluster. You can find instructions here: Porsche Boxster 996 Gauge Cluster Upgrade - 986 / 987 (1997-08) - Pelican Parts Technical Article