I have a 99 Honda Civic EX and it will randomly shut off in the middle of driving, not racing style driving, just regular everyday driving. I think it might have something to do with the heat (we had been in triple digits for a good while) At first it only seemed to do it when I turned on the AC but it has progressively gotten worse. Also, I used to be able to start it right back up after turning the AC back off, now I have to wait like 10 min. It doesn't do it all the time so trying to figure out what is causing it has proven to be quite the problem for me and the two shops I've taken it to. Anyone have any idea what could cause this?

 

Check your main relay. Open it and check for cracks in the solder joints. If it looks ok, check for spark.

 

This, with it being so hot the solder could be cracked, and as the relay get hotter, it shorts out. If you, or someone you know can solder, Have them just re-solder it to be safe and know it's good.

 

Thanks, I'll check that out

 

It turned out to be the ignition switch. Apparently that is a problem with these cars. Thanks for your input everyone