Wacker Neuson GP 3800A, Repair Manual

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Troubleshooting GP Repair
wc_tx000548gb.fm
106
6.26 Checking Anit-Afterfire Solenoid (AAS) Circuit
See Graphic: wc_gr003133
Electric shock hazard. Only qualified personnel should conduct this
test.
The AAS is located on the engine underneath the carburetor bowl.
Voltage may be prevented from reaching the AAS by: a faulty DC
winding, a blown fuse, a faulty engine ON/OFF switch, or a faulty
capacitor. To check the circuit, carry out the following procedure:
6.26.1 Check the 5A fuse. See section
Checking Voltage to Auto Idle
Solenoid.
6.26.2 Check the resistance of the DC winding. See section
Checking Auto
Idle Circuitry Between Generator and Fuse.
6.26.3 Check for voltage at the AAS by starting the generator, probing the
green and white wires
(a)
with your multimeter leads, then shutting the
engine off and measuring the voltage on the multimeter at shutdown.
There should be 18±2V.
•
If the correct voltage was measured, the AAS is malfunctioning;
replace it.
• If the correct voltage was not measured, continue.
6.26.4 Remove the screws that secure the control panel to the generator.
6.26.5 Check the continuity of the main ON/OFF switch. In the OFF position
it should have continuity across contacts 5 and 6—that is, between
wires W/R
(b)
and W
(c)
.
• If the main ON/OFF switch has no continuity, replace it.
• If the main ON/OFF switch has continuity, continue.
6.26.6 Disconnect the capacitor
(d)
.
A functioning capacitor can hold up to 30VDC; use care when
discharging it.
Discharge the capacitor by placing an insulated screw driver or like tool
across both of its leads. Then, check the capacitor’s capacitance. It is
rated at 1000 µF (microfarads) and should measure within 10% of that
rating.
•
If the correct capacitance is not measured, replace the capacitor.
• If the correct capacitance is measured, the capacitor is OK.
6.26.7 All major components of the circuit have now been checked. If the AAS
is still not working, check the continuity of all the wires in the circuit.
Repair or replace the wires as needed.
WARNING
CAUTION