1975 Plymouth duster brake relay question?
In the 1975 model year, there were two engine wiring harnesses.
Chrysler part #3843129 was used up to 10-14-74 and it had the interlock system.
Chrysler part #3843461 was used after 10-14-74 and did not have the interlock system. That was the reason for asking for the build date of the car.
There are 3 steps to permanently disable the system.
1. Reach under the seat and unplug the sensor.
2. Unplug the green or blue interlock module under the dash.
3. Splice together the two yellow wires going to the interlock relay under the hood.
If you don't want to cut and splice the yellow wires you can make a jumper cable. Take a 12 gauge yellow wire and crimp a male terminal on both ends, then plug the jumper cable into the interlock connector plug. This connects the yellow wires together instead of cut and splice.