Jake Brake/ High idle

[Ernest Ekberg]

My coach has tose 2 items. Tey use to work. While I had some time
today, I looked in the parts manual. On the electric high idle buffer
switch - that sits on top of the jake brake controller, the parts list
shows a diode attached to the 2 electric leads. On my coach, there only
remains a piece of wire- no diode. Does anyone know what that diode
might do? That thing may be the only reason, my Jake/high idle is
inoperative. Thanks, Ernie-83PT40, warm Montana