I recently bought a 2009 Ranger 2.3 4cyl. About 2 days after purchasing I noticed the airbag light on the dash comes on about 1-2 minutes after starting. There is no flashing code, it comes on and stays on. When someone is in the passenger seat the "Passenger Airbag Off" light comes on (next to the radio). The seatbelt light and chime do not engage when either driver or passenger is not buckled. The light on the dash definitely works, as I attempted the deactiate/reactivate and it successful disabled and re-enabled according to the instructions. Still there is no chime and the light doesnt come on when sealtbelt is off. I did notice it mustve started happening after I replaced the stereo. But, i wasn't replacing the stock radio. It already had an aftermarket alpine which I swapped out for a sony, it used all of the exact same wires and was very straightforward. I have checked and double checked all of the fuses and I verified all of the wiring under both seats are intact and connected. Not sure if the seat belt and airbag issues are due to the same problem but that's how it usually works when they both go at the same time. Any information helps. I apologize if this has been discussed, I couldnt find any threads for either issue (even searched them separately) which related to my issue.

 

some vehicles will have a place to turn passenger airbag on and off for child seats and such if it is turned off it will remind you when a passenger is in the seat my 02 ranger uses the key to turn off passenger air bags
not very helpful but might eliminate one part of the question