The Genie is a small engine coupled to a large alternator and it may run for extended periods at about 80% of its horse power. At this high load, there is no margin for fuel interruptions. Even a small air bubble can cause the unit to stall. Issues with the fuel supply are almost always the reason a diesel engine will not run.
Each Genie is equipped with a switch to sense overheating, and another switch that senses low oil pressure. Both switches connect to ground on one end, and to the Genie Controller on the other end. Switches are shown on the wiring diagram and can be identified by the wire colors connecting them.
The Genie Controller is a small electronic module which is supplied with the unit.
The H2O switch is normally closed, so an ohmmeter should show continuity to ground. The switch will open when the coolant is too hot.
The oil pressure switch is closed when there is oil pressure. An ohmmeter will not show continuity unless the engine is running.
The Genie Controller has a relay which is closed when the Genie is running. The relay closes during engine cranking, and will stay closed if there is oil pressure and the coolant is below the cut-off temperature of the H2O switch.
The engine is not capable of driving the alternator at full output. Alternator current limiting must be activated. Most Genie 12V/150 Amp units will stall at about 190 Amps.
For the following tests, set the current limit to about 130 Amps so that power overload cannot cause the engine to stall. Do not make the test without a load because fuel delivery problems may not cause the engine to stall.
Direct Fuel Connection
As mentioned, fuel supply is the problem in most instances where the Genie won't run, or runs for a short time and then stops. The following steps will eliminate the fuel solenoid as a problem.
First, locate the throttle arm on the engine and loosen the two nuts on the top of it so that the throttle arm can be moved. It must not move freely, but you should be able to move it by hand. Leave it open ... about 3/8ths inches from the stop.
To stop the engine, the throttle arm must be moved to the right, toward the alternator, as far as it will go. You will need to do this at the conclusion of this test.
Next, remove the fuel line between the fuel solenoid and the engine. Connect the fuel line from the tank directly to the engine, bypassing the fuel solenoid.
Now, start the engine as normal. The Genie Controller can not shut the engine off because the fuel solenoid is bypased. If the engine stalls then there is either a fuel problem, or air restriction.
Re-tighten the throttle linkage nuts to hold the throttle arm firmly in place at the conclusion of this test.
Hotwire the Fuel Solenoid
The Genie Controller provides a positive voltage to the red wire on the fuel solenoid. That wire is spliced to the yellow wire on TB5-3, and labelled Run on the wiring diagram.
Temporarily place a jumper between B+ on TB5-1 and TB5-3, hot wiring the fuel solenoid on. The Genie Controller can not stop the engine with the hotwire in place.
Start the engine and run it. It the engine stops, then it is either the fuel solenoid, or some other restriction in the fuel line.
Short the Oil Pressure Switch to Ground
The over temperature switch can be eliminated as a problem by shorting across the switch. The easy way to do this is to put a jumper between pin TB5-5, and ground on TB5-10. With this jumper in place, loss of oil pressure will not stop the engine.
Short the H2O Switch to Ground
The over temperature switch can be eliminated as a problem by shorting across the switch. The easy way to do this is to put a jumper between pin TB5-6, and ground on TB5-10. With this jumper in place, over temperature will not stop the engine.
The steps presented above will pinpoint the reason an engine stops unexpectedly. The tests will eliminate the fuel solenoid, the oil pressure switch, and the over temperature switch.
Bypass the fuel shut-off solenoid to eliminate a plugged orifice as the reason the engine stalls.
Hotwire the fuel solenoid connection to eliminate it as the reason the engine stops.
Short the oil pressure switch input to the controller to eliminate the switch as the reason the engine stops.
Short the H2O switch input to the controller to eliminate the switch as the reason the engine stops.
Ample Power products are manufactured by Ample Technology,
2442 NW Market St., #43, Seattle, WA 98107 - USA