Good suggestions above. To add to that, if you want to learn how to check the alternator voltage output yourself invest in a multimeter. The Harbor Freight $7 one is sufficient. You’ll find plenty of videos on YouTube how to take the alternator voltage measurements. You’ll find many other uses for the multimeter (such as locating the possible parasitic current draw on your Pilot) so it’s a very useful electronic debugging tool.
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I would concur with the above suggestions. Have the batter/alternator tested to make sure the problem is not with either one of them. From there if they check out fine check for a parasitic drain. Loose wire, stripped insulation etc. This is a good article for tracking down parasitic drains. Advance Auto Parts - Down for Maintenance There are also several good you tube videos on the same subject.
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We just recently purchased an 04 Pilot a month ago ourselves and had the same issue. We took it to O'reilly Auto Parts and had it checked which they discovered that we had a loose connection to the battery. They tightened up the connection and haven't had any issue since. I suggest taking it to an auto parts store to have the electrical system checked and make sure the connections are tight.
I’m going with OP forgot to check the box which sends email alerts when someone has responded to the thread. S/he is probably wondering why nobody has responded to the question. Hopefully OP comes back so we know the outcome.