Abstract: A circuit for compensating for failure of a light source includes a first light source having a first function and a first intensity associated therewith and a second light source having a second function and a second intensity associated therewith. A controller is connected to the first and second light sources, for detecting a current to the first light source. Upon detection of a failure of the first light source, the controller modulates the second light source to provide the function of the first light source with a substantially the first intensity.

Abstract: A pulse actuated clutch and control arrangement for coupling and decoupling a drive line of a vehicle relative to a wheel such as when shifting between two-wheel and four-wheel drive modes. The pulse actuated clutch has a coupling member that is permanently engaged with one of a driven member and a driving member. The coupling member is movable in a first direction to engage one of the driven and driving members and is movable in a second direction to engage both the driven and driving members. The coupling member is moved in the second direction by a first pulse of air pressure applied thereto. Formations of the piston assembly and the driven member cooperatively latch the piston in the second position to maintain the coupling member in engagement with both the driven and driving members following first pulse of air pressure. A second, greater magnitude pulse of air pressure moves the primary piston further to unlatch the piston and uncouple the driven member from the driving member.

Abstract: This is a method and apparatus for operating a transfer case of a four wheel drive vehicle wherein sensors detecting rotation of the front and rear drive shafts speed are scaled to produce an advantageously accurate representation of vehicle speed. The method generates a scaling factor by comparing stored information to information sensed by rotational sensors on the front and rear drive shaft.