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12.
DC OUTPUT CIRCUIT TESTING
First verify that the battery pack voltage is present at the battery receptacle. If it is not, a fault
has occurred in the vehicle’s wiring. Remove the Phillips screws that retain the cover, then
remove the cover. Connect the DC output plug to the battery receptacle and with a multi-
meter measure the voltage inside the charger where the WHITE and BLACK wires of the DC
output cord attach. If the battery DC voltage measured inside the charger is not present, the
DC output plug or cord has an internal break and must be replaced. If the battery pack voltage
is measured inside the charger, remove the DC output plug from the battery receptacle.
Check the charger fuse and if blown, refer to Troubleshooting Guide SECTION 2.
Set the multi-meter to measure resistance and connect the test leads to the charger DC output
plug terminals and note the readings. Reverse the tester leads and check the DC output plug
again. The circuit should be complete in only one direction. If the circuit does not conduct in
either direction and the DC output fuse is good, individually check the continuity of the DC
output cord, ammeter, diodes, and all connections. If the circuit conducts in both directions, a
short exists in the charger DC circuit. First check the DC output cord for a short between the
two wires. It is more likely that one or both diodes have shorted. Refer to SECTION 9 “Diode
Assembly Testing” for further diode testing procedures.
If the charger DC circuit test is good, a check of the capacitor is necessary. Refer to SECTION
10 "Capacitor Testing" for further test procedures. If the capacitor is open or shorted, it must
be replaced.
CAUTION: USE ONLY THE PROPERLY RATED CAPACITOR FOR REPLACEMENT.
THE USE OF A DIFFERENT VALUE CAPACITOR MAY RESULT IN IMPROPER
CHARGING, CAPACITOR FAILURE, TRANSFORMER BURN-OUT, AND/OR BATTERY
DAMAGE.
If the charger DC output circuit and capacitor check good, a test of the transformer is
necessary. Refer to SECTION 8, "Transformer Testing" for test procedures.
CAUTION: BE SURE ALL CONNECTIONS ARE CLEAN AND TIGHT. ALSO CHECK
TO BE SURE ALL WIRES AND TERMINALS ARE POSITIONED SO THEY DO NOT SHORT
TOGETHER OR TO THE CHARGER CASE.
