Realize this is an older thread, but I ran into the same issue with the beeper (travel alarm) going off anytime you touch the pedals. This thread helped me to come up with a solution, so figured I would pass it on to help someone else as finding things was most of the problem.
Basically, I accessed under the pedals and disconnected the wire harness leading to the sensor switch which turned out to be a DT 2-pin style, Found a male/female set of DT 2-pin wire leads and a waterproof 12V switch on Amazon, put that together and was able to just snap it in so it will be easy to remove later if desired. Access to where the wire harness plug is required the removal of a 13mm bolt inside the locked compartment below the cab door. Once that is out there are two 13mm bolts under the front of the cab to remove an access panel in front and under the pedals. With both open you can just reach in to disconnect the wire loom harness leading up to the pedals and then insert the improvised switch. Hopefully, the pics will illustrate what I am saying.
Now, if I am working and want the warning alarm on, I just open the panel and flip the switch.
For similar products used, search:
-Set DT 2 Pin Male Female Wiring Harness Connectors
-12V Inline Cord Switch IP67 Waterproof, Outdoor ON/Off Toggle Switch DC 12V-24V with Red LED Rocker Button, 20A Inline Power Switch 12 Volt On Off Switch Two-Side Entry and Exit Line