Why won't my car turn over but the lights and radio work?

Check for problems with the starter, either a loose wire or the starter is bad.

First thing to check is the connections to the battery, and then the battery itself.

The heavier the load you try to pull from a battery, the more it can be affected

by dirty connections to the battery.

The radio may be the lightest load of all. The radio will run even if the battery posts are

caked with goo and grime and one strand of wire pokes through and makes contact.

By far the heaviest load of all in a car is the starter. And plus, when you're starting,

the car's alternator doesn't help a bit electrically because it's not running yet, so it

ALL has to come from the battery. If there's a loose clamp on one battery post, or

dirt built up on them, or some broken strands in the cables connected to the battery,

then the juice literally can't get from the battery to the starter fast enough to run it.

One at a time, disconnect each clamp from the battery, clean the battery post

and the inside of the clamp with a wire brush and some baking soda or abrasive

cleanser (Ajax, Comet) in hot water, dry it off, and reconnect it good and tight.

If it doesn't start up right away, remember that in order to charge the battery,

the juice has to go in through the same places, so make sure the battery is well

charged before you decide that cleaning the contacts didn't work.

Two good reasons to try cleaning the battery contacts first:

#1). It's a common cause of what you're describing.

#2). It's the cheapest, easiest fix to try.