Two fold question. For info I have the Lariat 502a with the keyless ignition.

When looking through my owners manual it talks about programming a spare intelligent access key, not to be confused with the integrated keyhead transmitter (page 74). I'm confused, in step 1 it says to put the first programmed key in the backup slot and then do stuff and then put the first previously programmed key in the ignition. Where is the ignition? Also, the first bold part above I'm guessing I put the whole key fob (the "first programed key") in that hidden slot under the mat in the storage in front of the shifter? Then the second bold part above "first previously programmed key" is the actual key inside the fob? But still where is the ignition slot?

This leads to another question. What happens if the batteries die in the key fob if there's no ignition slot???