Q: Replaced the purge valve solenoid in my Buick rendezvous now the car won't turn over

Hi there. Anytime you complete repair or replace mechanical components, it is critical to remove the battery terminals before any further steps. It is possible that if the battery cables were not removed, that you’ve burned a fuse or relay. However, it’s also possible that you’ve got a parasitic battery drain non-related to this problem. I would recommend first charging your battery to see if this allows you to start the vehicle. If this doesn’t work, it’s likely that the ignition relay or other relay is damaged, which would be best to be diagnosed by having a professional mechanic come to your location and complete a car is hard to start inspection.