I have a 2005 2500 cargo van with a 4.8L or 5.3L V8. I was driving to work the other day and the check engine and ABS light both came on yet the van continued to run. When it was time to go home, the van would not start. I turn the key to the on position and the guages all activate. I then turn the key fully to start and every guage drops but the check engine light remains on. In hopes of an easy fix, I pulled the starter to test it and it worked fine. With no starter attached, the same results occurred when turning the key to start. Any help trouble shooting this would be great, thanks.