Waterous E500 Series, Operation, Maintenance And Overhaul Instructions

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Controller and Engine Troubleshooting Guide
(Cont’d)
Problem Fix
Engine Shutdown, Temp Lamp Displayed
Check radiator for blockage.
Once engine has cooled down, check coolant level.
Check functionality of thermostat.
Verify actual coolant temp and compare to temp displayed.
Engine Doesn’t Shutdown
In single controller applications, check for jumper on 8-pin auxiliary
controller connector.
Check shutdown solenoid. Shutdown solenoid should energize
when the controller is turned off. Momentarily apply 12v to solenoid
to test functionality (solenoid will burn out if 12v is applied
continuously).
Check 15A fuse on WH00023 main controller harness.
Check for backed out terminals in controller engine harness 12-pin
Deutsch connectors.
Check energize-to-stop timer for proper function. Refer to engine
harness schematic WH00046. R-Y 16 wire provides the 12v run
signal when the controller is turned on. When the run signal is
removed the W 14 wire going from the ETS timer to the stop
solenoid should energize. If the timer is getting a good ground, +12v
battery power and run signal but doesn’t energize the W 14 wire,
replace the timer. (The timer also is responsible for returning the
speed control lever to idle. If the timer is bad, the speed will not
automatically return to idle at shutdown).
Engine Speed Doesn’t Respond To Input
Make sure 2-pin speed control connector and 3-pin MPU connector
are connected to their mating connectors on engine harness or
auxiliary controller connector.
Check for backed out pins in 2-pin and 3-pin connectors.
With engine running, verify the controller is displaying rpm. If no rpm
is displayed, check the magnetic pickup sensor mounted near the
front crank pulley. The controller uses the rpm signal to verify the
engine is running. The controller won’t enable the speed control
system until the engine is running.
Verify speed control linear actuator functionality by applying ground
to terminal #1 and 12v to terminal #2. Then, apply ground to
terminal #2 and 12v to terminal #1. The linear actuator should
extend and retract depending on the polarity of the power applied
(unless the linear actuator is at the limit of travel in that direction). If
the linear actuator doesn’t move, it may be defective.
Engine Runs Rough
Check for air bubbles in fuel supply and white exhaust.
Check quality of fuel.