Ok this may be a stupid question but why do these trucks not have an accessory key position? (1 turn backwards)
It seems when I turn the key one click forwards I get the power I want (mainly for radio with engine off) but sometimes all the dash lights light up, sometimes it's just a few like battery etc etc.

Also when I turn the key to the off position the radio will stay on for a few minutes but sometimes all the dash lights stay on and sometimes they all turn off except the radio. Only way to turn off the dash lights is to open the door which sghuts off the radio.

I noticed this at the drive-in last weekend