When I turn the key to the on position the starter tries to kick in and out and the dash lights and gauges flicker on and off. If the engine does start the starter keeps trying to engage.I've replaced the starter and ignition switch checked all connections and grounds.

. Remove and fully charge the battery--do this first. Most auto parts stores will do this for free.

. Test all under hood and under dash fuses with a test light or multimeter.

. Check the harness from the ignition switch to the under dash fuse box.

. Check the ignition switch, again, if the problem persists.