Generac Power Systems GTV-990 Manual page 20

SECTION 2: IGNITION
1. Insert RED test lead into
2. Insert BLACK test lead into the "COM" receptacle in meter.
3. Rotate selector to
4. Insert RED test lead clip into connector "A" (Figure 2-10).
Leave attached for remainder of test.
5. Touch BLACK test lead probe to terminal "B."
a. If meter "Beeps" once, diode is OK.
b. If meter makes a continuous tone, diode is defective
(shorted). Replace ground harness.
c. If meter displays "OL," diode is defective (open). Replace
ground harness.
6. Now repeat test for terminal "C." Results must be the same.
See "Diode Failure Diagnosis" below.
receptacle in meter.
(Diode Test) position.
Figure 2-11. Engine Wiring Harness
DIODE FAILURE DIAGNOSIS
SWITCH ON
Engine Runs Shuts Off OK
On 1 Cylinder
Engine Runs Only One Cylinder
(Both Cylinders) Shuts Off
Won't Run
(No Spark)
Engine Runs Engine Won't Shut Off
(Both Cylinders)
ENGINE
GROUND
HARNESS
A
POSITIVE METER
TEST LEAD
Figure 2-10. Testing Ground Wire
TURNED OFF
1 Closed Diode
1 Open Diode
2 Closed Diodes
2 Open Diodes
2-4
B
NEGATIVE METER
TEST LEAD
IGNITION KILL WIRE
CAUSE
C