718 Drivers mystery button

[Ulysses]

Hi everyone.

Does anyone know what this red button do ? It is located beside the engine on the drivers side (RHD) with "twist to lock" written on it. This 718 was an ex firetruck so perhpas something to do with the pumps ? Our thought was that it may be used for locking drive selections but this (automatic) vehicle has dash button selectors for 6x6 etc. Feedback much appreciated ... photos attached.

[David Dunn]

There's no pic. though there are many deviations in the TDs, the basic activations are all the same. Is the button electric or mechanical ? Where does it go to?

[Ulysses]

Sorry about that ... it was a format problem. Here are two photos, of the button and placement next to engine , drivers side.

[David Dunn]

Definitely not standard to Pinzes, but first thought would be a high idle engine control for a PTO (assuming your fire truck has one)
It looks like a cable control, so remove the engine bay top cover and see if there is an extra cable to the injection pump. It would raise the idle and not interfere with the acceleration cable