Working on an 86 S10 Blazer 2.8L 6cyl 4X4. Will crank over but won't start. Also noticed the radio backlighting, dome lights and horn suddenly did not work. Replaced the ECM unit (hasty decision-I know, but with the multiple sudden failures, made sense at the time.) Ran a diagnostics on him,but there are no codes...it's an '86. Tested the fuel pump and lines with a voltmeter. Now replaced, but still will not start. Has a new Optima battery and cranks over strong. Used some starter fluid to get it to start, but will not stay running. Am now looking for the FPR and will try replacing that, AND re-wiring the electrical lines connected to the entire fuel pump system. Perhaps an electrical short somewhere? OR any ideas ? I am no novice to auto repair or diagnostics but this is really boggling my mind. Sure would welcome any insight, tips or shade tree hints for zeroing-in on this multifaceted problem. Gotta get my little autobot up and crawling again. Thank you in advance... Dzr