I have a 1997 1500 Savana Van with 140,000 miles. 5.7 Engine. ABS light came on. Brake light came on. Service Engine Soon came on. Lights went off and came back on twice then everything shut down. When I try to start the engine it came on but quit when I let go of the key. Then could not start van. Took battery cable off let sit for an hour then van started back up and has been working fine. Any thoughts of what could be wrong? Thanks for any help.