What could the problem be will not crank or start and some dash lights stay on

Every one of these that I have repaired was doing the same thing, starter relay under dash buzzing because the ignition switch wasn't sending enough voltage to completely close the relay .. Replacement of the ignition 'electrical' switch fixed the problem! http://www.youtube.com/watch?v=a_ZyEl8j3hI Really should check out the video link above. PART # NAPA ECH KS6903 > FITMENT - 2001 Honda Odyssey ▪️Now > good luck to you!!▪️

No it has not started since the day I went to store. I've cleaned the battery post and cables. Don't know where to find starter relay at? Jump starting did absolutely nothing. Now when I try to start van those same lights I said in my first post are still on and there is a hissing noise when I turn the key but won't crank or start still

Starter solenoid , not relay , is on the starter. Hissing noise maybe a buzzing inside the vehicle?? THAT could be the relay. That would/could buzz if too low voltage. ALL require testing.