Ignition Test Procedures; Direct Voltage Adaptor (Dva) Test - Mercury 40 Service Manual

Ignition Test Procedures

Direct Voltage Adaptor (DVA) Test

CAUTION
DVA checks can be made while cranking engine
with starter motor. To prevent engine from start-
ing while being cranked, all spark plugs must be
removed.
CAUTION
To protect against meter and/or component dam-
age, observe the following precautions:
INSURE that the Positive (+) meter lead is
connected to the DVA receptacle on the me-
ter.
DO NOT CHANGE meter selector switch posi-
tion while engine is running and/or being
"cranked".
NOTE: Each CDM is grounded through the engine
wiring harness via the connector plug. It is not neces-
sary to have the CDM mounted on the ignition plate
for testing.
1. Remove all spark plugs.
2. Insert spark gap tool (P/N 91-63998A1) into each
spark plug boot and attach alligator clips to a
good engine ground.
3. Disconnect remote fuel line from engine.
4. Make sure all CDMs are plugged in.
5. Test Stator and Trigger voltage to CDM:
a. Install test harness (84-825207A2) between
ignition harness and CDM.
a - Stator/Trigger Harness
b - Test Harness (84-825207A2)
c - Capacitor Discharge Module
b. Test each CDM.
2A-20 - ELECTRICAL
Stator Output Test
Positive Meter Negative
Lead (+) Meter Lead (–)
Connect to Connect to
Green Test Black Test Har-
Harness Lead ness Lead
If only one CDM stator reading is below specifications,
replace that CDM. If all CDM stator voltage readings
are low, go to "Testing Stator Resistance".
Test each CDM.
Trigger Output Test
Positive Meter Negative
Lead (+) Meter Lead (–)
White Test Black Test Har-
Harness Lead ness Lead
If reading is below specifications, replace trigger. If
reading is above specifications, check CDM.
400 DVA
Scale
DVA
Reading
100 - 350
2 DVA Scale
DVA
Reading
0.2 - 2.0
90-852572R1 JANUARY 1998