Replaced Battery, Now No Response Turning Key

A common problem people who aren't necessarily DIY mechanics run into is this: they replace their car's battery and then turn the key and get no response.

Often this creates confusion because accessories (lights, radio, etc) work just fine even though the car won't "turn over" when the key is turned. Luckily, this is nearly always a simple problem with a simple fix.

It's usually a faulty battery connection. Here are five quick steps to easily check and, if this is the problem, fix it:

1) remove the battery terminal connections.
2) check those for decay and clean them thoroughly. If the wires are frayed at all (usually on the positive side, but either can be), that could be your problem and definitely requires fixing.
3) check the battery posts for cleanliness (even new batteries can have oxidation). Clean them if needed.
4) put a meter on the battery and check that it's fully charged - even new batteries aren't always full when purchased.
5) reconnect those terminals and make sure they are tight. A good SOP is to connect them somewhat loosely (if using "post" type) and then rotate the connector on the post to "rough up" the two, then tighten to spec.

Nearly every time, one of these steps will resolve the problem. It's unlikely that a car that was working just fine will suddenly break something serious just because the battery was replaced (assuming the replacement battery is of proper size, cranks, etc).