My dash lights (all) delay coming on after I start the engine.

For a while now my dash lights (speedomoter, rpm meter, etc, etc [I don't know what their called]) delay lighting up on my dash after I start the engine. After a few seconds they usually light up but today I had to turn the engine off and restart it twice before they came on. My battery died a few weeks back when I had the radio and A/C on for 20 minutes without starting the engine, I replaced my battery 1 week ago, but this problem preceeds the battery replacement by months. I tested the alternator and it seems low so I may replace it but I'm not sure this problem is a result of the battery or alternator...I would appreciate any clues. VIN 1GNEC13V54J266101. thanks.