1996 Dodge Caravan Van will try to start but it wont start

Start some time run no problems if I stop the engine will not start again tries to start after few second dies will start after 6 or 7 hr I changed my plugs before this problem the thing I checked relays fuses all good the only thing I noticed when its not start at that time I don't see any power to the speedometer fuel heat and rpm and also not showing the park. Nut.R. Digital signs on the upper dash I can see oil can sign abs parking brake after turning the switch to on position engine tries to start and after starting it dies. But when ever I see all gags move I know the van will start. Any buddy know what the hell is going in my life with this van.I cant go no where because I know it may not start iand I have to leave it the for 6 to 7 hr please help me