Honda 2004 Odyssey Service Manual page 110

Alternator and Regulator Circuit Test
1. Be sure the battery connections are good, and that
the battery is sufficiently charged. (see page 22-87).
2. Connect a VAT-40 (or equivalent tester), and turn
the test selector switch to position 1 (starting).
LOAD ADJUSTER FULL FIELD TESTER
(CARBON PILE)
LEAD (BLU)
VOLT
SELECTOR
FIELD
SELECTOR
TEST SELECTOR
SWITCH
B TERMINAL
3. Shift to Park or Neutral, and start the engine. Hold
the engine at 3,000 rpm, with no load until the
radiator fan comes on, then let it idle.
4. Raise the engine speed to 2,000 rpm, and hold it
there.
Is the voltage over 15.1 V ?
YES Replace the voltage regulator.
NO Go to step 5.
5. Release the accelerator pedal, and let the engine
idle.
6. Make sure all accessories are turned off. Turn the
test selector switch to position 2 (charging).
7. Remove the inductive pick-up, and zero the
ammeter.
8. Place the inductive pick-up over the B terminal wire
of the alternator so that the arrow points away from
the alternator.
VOLTMETER
NEGATIVE
LEAD (BLK)
VOLTMETER
POSITIVE
LEAD (RED)
NEGATIVE TESTER
CABLE (BLK)
POSITIVE TESTER
CABLE (RED)
INDUCTIVE
PICK-UP (GRN)
INDUCTIVE PICK-UP
9. Raise the engine speed to 2,000 rpm, and hold it
there.
Is the voltage less than 13.5 V ?
YES Go to alternator control system test.
NO Go to step 10.
10. Apply a load with the VAT-40 until the battery
voltage drops to between 12 13.5 V.
Is the amperage 7 5A ( 87 .5A f or 2002-2004
models) or more?
YES The charging system is OK.
NO
1999-2001 models: Go to step 11.
2002-2004 models: Go to Alternator Control
System Test.
11. With the engine speed still at 2,000 rpm, full-field
the alternator. Attach the probe to the VAT-40 full-
field test lead, and insert the probe into the full field
access hole at the back of the alternator. Switch the
field selector to the ''A (Ground)'' position
momentarily, and check the amperage reading.
Because voltage will rise quickly when the
alternator is full-fielded, do not allow the voltage to
exceed 18 V: it may damage the electrical system.
END
COVER
Is the alternator output 7 5A or more?
YES Replace the voltage regulator.
NO Go to Alternator Control System Test.
REGULATOR
(Located inside
the end cover)
FULL FIELD
ACCESS HOLE
(cont'd)
4-23