I own an 04 prius with 108 k, no warranty. I plan on using it as a postal vehicle on a rural route. I need to deliver out of the right side window, and with that in mind, found a bench seat from a mini pickup that bolts up with minor mods. My quick solution to dealing with the switch/sensors in the seats is to simply rewire at the connections, at least that's my plan. I would configure it so both seats are always occupied. (Simply removing the passenger seat has turned on the air bag light, and I won't use the car without airbags). I have limited electrical experience, thought of simply voltage testing the wires of an occupied seat,and then rewiring to simulate. Has this been posted? I also have the seat airbag wiring to deal with. For me, the added control from driving from the middle of a bench seat (for my job) offsets the loss of the seat airbags. I plan on using a rear seat buckles for the front seat. Yes, no children will be in the car.
Try a search on this site, there have been several recent posts on this subject from other letter carriers/paper delivery owners complete with pictures of conversions.
I would like to bypass the pass seat also. My briefcase is so heavy it turns on the pass belt so I have to engage the pass seat belt all the time. I need to bypass in a way that you can still use it for passengers though. Neat trick! I bought a Prius Chiltons on Amazon a few days ago. Hopefully there'll be a diagram in it. Probably not. I searched "Bypass seat belt" but no joy. If not in the Chilton's I'll try the online subscription thing. I'll post if I find anything.
Theres a plug located under the seat, this connects to a sensor that when it is depressed on triggers the passenger seatbelt light. Thats it. Lucky you dont have a 06-08 prius, they have a occupant classification system, where if u disconnected it it would trigger the SRS warning light.
Simply removing the passenger seat has turned on the air bag light, and I won't use the car without airbags) I went out and checked, my '04 prius without any seat connectors connected, will have the little red belted figure with red ball ON, (which is the SRS indicator light), and strangely, the driver's and passenger's seat belt icon is not on.
