2000 Dodge Ram problems starting

If you have a digital odometer, sometimes you can get codes there? You cycle key just till dash lites come on, no further. On--off, on--off, on, then watch the digital odometer. At the datalink connector, does pin 16 have voltage, should be hot all the time. Yeah, I need to find a better picture of that data link connector.

When the problem occurs, have helper crank it, while you visually check for spark at the plugs, you can carry a known good spark plug or spark tester in the glove box, then pull spark plug wire, where applicable, put tester in boot, ground metal part of tester or plug to metal part of engine, watch for spark. If spark everywhere, use a gage and check fuel pressure.