I ran new cable back from the engine compartment to the trailer wiring
recepticle to replace old ratty stuff and I have moved some wiring
some where under there because the "antilock brake light/buzzer "
is now on. Every thing works just fine, never touched the brakes.
Where is the sender that generates the signal for the buzzer ??
1991 350 dually, Cummins/5 speed , low milage. Thanks.

 

I think it is on the RWAL.that is mounted on the drivers side rear in the frame near the axle.