8
Refer to the Troubleshooting Guide for the WF-8900-AD-MBA Series Main Board Assembly
(Figure 4 on page 9).
CONVERTER OUTPUT VOLTAGE
Before checking the WF-8900-AD-MBA Series Main Board Assembly output voltage, disconnect
the battery cables at the battery. Make sure the converter is plugged into an AC source (105-130
Volts). Check the converter output voltage at the battery with a voltmeter. Place the meter probes
on the disconnected battery cables; place the
Positive
(red) meter probe on the
+ Positive
battery wire and place the
Negative
(black) meter probe on the
- Negative
wire on the battery
cable. Be sure you have good connections at the cables. If the voltage reads 13.6-14.6V the
converter is functioning properly.
If the converter output voltage at the battery reads 0.0 VDC, or if the battery is not charging,
check for an open in-line fuse in the battery wire circuit. One may have been installed by the RV
manufacturer. Also check for loose wiring connections.
DC REVERSE POLARITY (FUSES)
If there is no DC output coming from the WF-8900-AD-MBA Series Main Board Assembly con-
verter section, first check the reverse polarity fuses on the fuse board. Then, visually inspect the
fuses for any breaks in the fuse element. If no breaks are found, use a continuity tester to check
for continuity. If the reverse polarity fuses are blown, it means the RV battery was accidentally
connected in reverse, either at the battery or at the converter. Investigate the connections and
reconnect the cables properly. Replace the fuse with the same type and samperage rating as the
original.
IMPORTANT:
These fuses protect the converter from damage in the event that the RV battery is
accidentally connected in reverse. A reversed battery connection, even if for only a second, will
cause these fuses to blow.
TROUBLESHOOTING INSTRUCTIONS
Troubleshooting the WF-8900-AD-MBA Series Main Board Assembly
