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I had posted this elsewhere (https://www.promasterforum.com/forum/showthread.php?t=44985&page=5) but realized it should really be in the electronics forum, so I shall summarize here.

I'm in the process of trading my front bench seat for a single passenger seat. Once swapped, the ABS system will throw an error because the 3 sensors/devices that were in the center seat are no longer available. Those sensors are:
1) the seat weight sensor
2) the seatbelt pretensioner
3) the seatbelt catch sensor

The only solution I was able to find to this issue was a post about purchasing a second set of these sensors/devices from Mopar, connecting them, and then stowing them under the passenger seat. Seeing as how the parts now cost $300 shipped, I decided I'd rather find another solution. So I spent a day troubleshooting and testing and found the following:

Seat weight sensor is connected to the vehicle through a white 2-pin connector under the seat. It is factory calibrated at 0, 50, 60 and 100lbs. The sensor is a resistive strain gauge where resistance is lower the more weight is on it. My sensor read 400ohms with the seat unoccupied. I replaced this sensor with a 400ohm resistor, and the airbag error light did not turn on. If you are doing this same conversion, be sure to test your sensor before giving away your seat, because of the calibration, it might not match mine.

Next the seatbelt pretensioner and the seatbelt catch sensor are both on an orange plug under the seat. It has a built-in spring clip so when the sensor is disconnected it automatically shorts all pins (I'm assuming to avoid accidental airbag or pretensioner explosions). The pretensioner is an explosive device attached below your seatbelt catch that will tighten belt about 4" in the event of a crash. It read 2.7ohms on the black and yellow wire pair (colors on the sensor side), so I replaced that with a 2.7ohm resistor, and again, everything worked fine.

Finally, the seatbelt catch sensor, which are the black/red pair of wires in the orange connector mentioned above. This one is a unipolar hall effect type sensor inside the seatbelt catch. It gets 1.22v on the red wire from the vehicle, and is grounded to the vehicle ground. When the belt is inserted, it passes 0.61mA and 0.25mA when unclipped. Since I want to replicate the unclipped mode of the sensor, I used ohms law to calculate that I'd need a 4.8k resistor to mimic this sensor in an unclipped mode. I added that resistor between the red wire and vehicle ground and again, everything works fine when I start the vehicle. For some reason, when I measured the current on the wire with the resistor, it now read 0.16mA, so I must have gotten something wrong, but it's working for now...

We shall see if this holds true when it's not 95F outside.


Hope this helps someone in the future.

-Tom
 

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Thanks for all your hard work and valuable information Tom. I’m sure it will be a big help for many. People.

We do have to keep in mind this is all about switching from a double to a single seat and for everyone’s protection, of course, don’t try this unless you are competent and know what and why you’re doing it - as Tom seems to be ;)
 

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I had posted this elsewhere (TRADE WANTED: Offering front passenger bench for in...) but realized it should really be in the electronics forum, so I shall summarize here.

I'm in the process of trading my front bench seat for a single passenger seat. Once swapped, the ABS system will throw an error because the 3 sensors/devices that were in the center seat are no longer available. Those sensors are:
1) the seat weight sensor
2) the seatbelt pretensioner
3) the seatbelt catch sensor

The only solution I was able to find to this issue was a post about purchasing a second set of these sensors/devices from Mopar, connecting them, and then stowing them under the passenger seat. Seeing as how the parts now cost $300 shipped, I decided I'd rather find another solution. So I spent a day troubleshooting and testing and found the following:

Seat weight sensor is connected to the vehicle through a white 2-pin connector under the seat. It is factory calibrated at 0, 50, 60 and 100lbs. The sensor is a resistive strain gauge where resistance is lower the more weight is on it. My sensor read 400ohms with the seat unoccupied. I replaced this sensor with a 400ohm resistor, and the airbag error light did not turn on. If you are doing this same conversion, be sure to test your sensor before giving away your seat, because of the calibration, it might not match mine.

Next the seatbelt pretensioner and the seatbelt catch sensor are both on an orange plug under the seat. It has a built-in spring clip so when the sensor is disconnected it automatically shorts all pins (I'm assuming to avoid accidental airbag or pretensioner explosions). The pretensioner is an explosive device attached below your seatbelt catch that will tighten belt about 4" in the event of a crash. It read 2.7ohms on the black and yellow wire pair (colors on the sensor side), so I replaced that with a 2.7ohm resistor, and again, everything worked fine.

Finally, the seatbelt catch sensor, which are the black/red pair of wires in the orange connector mentioned above. This one is a unipolar hall effect type sensor inside the seatbelt catch. It gets 1.22v on the red wire from the vehicle, and is grounded to the vehicle ground. When the belt is inserted, it passes 0.61mA and 0.25mA when unclipped. Since I want to replicate the unclipped mode of the sensor, I used ohms law to calculate that I'd need a 4.8k resistor to mimic this sensor in an unclipped mode. I added that resistor between the red wire and vehicle ground and again, everything works fine when I start the vehicle. For some reason, when I measured the current on the wire with the resistor, it now read 0.16mA, so I must have gotten something wrong, but it's working for now...

We shall see if this holds true when it's not 95F outside.


Hope this helps someone in the future.

-Tom
Do you happen to have any pictures of how you installed the resistors? I’ve done it on boards before but curious to your process on the actual connectors.
 
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