Electrical System Operation; 12 Volt System - Toro Groundsmaster 5900 Series Service Manual

Electrical System Operation

12 Volt System

24 Volt System
Groundsmaster ® 5900 & 5910
16227SL Rev B
Groundsmaster 5900/5910 machines use two (2) separate electrical systems.
Most machine functions operate on a typical 12 VDC system. The second
system exists to operate the electric cooling fans and is 24 VDC.
Engine electrical components, machine operation switches, hydraulic solenoid
coils, the machine Toro electronic controllers (TECs), the Yanmar engine Engine
Control Unit (ECU) and the InfoCenter display are all included in the 12 VDC
system. Two 12 Volt batteries located at the rear of the machine are connected
together in parallel to support the 12 Volt electrical system. The 12 Volt system is
charged by an 80 Amp 12 volt alternator driven by a single row V- belt mounted
to the engine.
Circuit protection for the 12 VDC system includes a variety of fuses located in the
front or rear power centers and a pair of fusible links integrated into the starter
circuit wiring. Additional fuses are located in the cab headliner of Groundsmaster
5910 machines.
The 12 Volt system uses the vehicle frame as a ground. A battery- disconnect
switch is included on the machine which should be used to disconnect the
12 VDC and 24 VDC system components from the electrical power supply
to prevent component damage or unexpected component operation when
performing service.
Information about electrical components in the 12 VDC system is included in the
Component Testing and Service and Repairs sections of this chapter.
Groundsmaster 5900/5910 machines include two 12 Volt batteries located at
the rear of the machine that are connected together in series to support the
24 Volt cooling fan circuit. The 24 Volt system is charged by an 105 Amp 24
Volt alternator mounted to the machine frame. The 24 Volt alternator is driven
by a pulley attached to the engine crankshaft and a multi- row V- belt. Circuit
protection for the 24 VDC system includes a pair of fuses located on the rear
power center.
The 24 Volt system is an isolated system so the vehicle frame IS NOT used as
a ground in the 24 volt system. A battery- disconnect switch is included on the
machine which should be used to disconnect the 12 VDC and 24 VDC system
components from the electrical power supply to prevent component damage or
unexpected component operation when performing service.
Groundsmaster 5900/5910 machines include two (2) panels of cooling fans. One
panel cools the radiator and the other cools the hydraulic oil cooler. Each panel
includes two (2) 24 volt cooling fans operating at the same speed and direction.
All four cooling fans are identical.
Each of the four (4) fan assemblies include the 24 VDC fan motor and a 12 VDC
fan controller. The cooling fan motors receive power from the 24 Volt system
contactor. Using inputs from the coolant temperature sender and the hydraulic
oil temperature sender, the master TEC works with the internal fan controllers as
necessary to control the fan speed and direction. In return, the fan controllers
provide a hard wired fault signal used as an input to the master TEC as the
cooling fans are not on the CAN- bus system (see
(page 6–8)).
Page 6–7 Electrical System: Electrical System Operation
CAN−bus Communications