I have a 2000 4×4 blazer. It ran fine. Drove it half the day. Came home and parked it. Went back outside an hr later. It started right up no issues. As soon as I put it in gear it died instantly. Now it will not turn the starter over at all. Battery is good. All accessories work when you turn the ignition on. Put it in neutral same issue. Will not even attempt to turn over. I have checked all fuses and relays they are fine. What can cause the engine to instantly die when put in gear? How can that cause it to not even attempt to crank now? Any advice is welcome.

 

See if you have power to the crank fuse in the under hood fuse block with the ignition in the start position.

George

 

Several items: loose battery cable, failed ignition switch, battery, corrosion, just to list a few. Do the dash lights, headlights come on?

Time to start troubleshooting.

 

Bad vacuum leak?