EXPORT IQ PLUS CHARGER (EXTERNAL)
Test Procedures
2008 Export Battery Charger Maintenance and Service Manual
Page 5-19
5
5. Reverse test probes and check each diode again and note the reading
(Figure 5-12, Page 5-19)
. A
diode is designed to conduct current in one direction only. If a diode conducts current (shows continuity)
in both directions, the entire heatsink with diodes must be replaced. If a diode does not conduct current
(does not show continuity) in either direction, the entire heatsink must be replaced.
6. On rare occasions, a single fuse link may blow due to excessive heat. This can be caused by a loose
internal fuse connection. Check all three fuse connections inside the charger to be sure they are clean
and tight. The proper tightness for the fuse link connections is 22 in-lb (2.5 N·m).
7. Ensure that the charger is wired properly and all connections are clean and tight.
See following CAU-
TION.
CAUT ION
• If connections are not clean and tight, excessive heat will be created and the charger may
become damaged.
Test Procedure 4B – Both Diodes Failed
See General Warning, Section 1, Page 1-1. See additional WARNING on page 5-1.
To check the diodes, use Test Procedure 4A – Single Diode Failure on page 5-18. If both diodes have failed
closed, both charger fuse links will be blown. If both diodes have failed open, the relay will close and the trans-
former will hum, but the ammeter will not indicate any output and the AC circuit breakers may trip off. If both
diodes have failed open or closed, the entire heatsink must be replaced. To determine why both diodes failed:
1. Check the batteries and the receptacle to ensure that they are wired in the correct polarity
(Figure 5-2,
Page 5-3)
. Also check the voltage and polarity at the receptacle.
2. Make sure the charger is wired correctly: the DC cord red wire should be connected to the center terminal
of the heatsink, the DC cord blue wire should be connected to the limiter, which connects to the relay coil,
and the DC cord black wire should be connected to the left side of the ammeter (when viewed from inside
the charger)
(Figure 5-6, Page 5-9)
. If a reverse polarity connection is made between the charger and
the batteries, both fuse links will blow when the DC cord is connected to the vehicle, whether or not the
AC cord is plugged into an outlet.
3. On rare occasions, both diodes may fail as a result of a lightning strike at the charging location.
4. Excessive heat due to a loose connection may also cause both fuse links to blow. Be sure fuse connec-
tions are tightened to 22 in-lb (2.5 N·m).
5. Ensure that the charger and vehicle are wired properly and all connections are clean and tight.
Figure 5-11 Diode Test
Figure 5-12 Diode Test – Probes Reversed
Disconnect
secondary
coil lead.
