Advanced Marine Electrics and Electronics Troubleshooting A Manual for Boatowners and Marine Technicians

that its measurement range (up to 700 amps)
is not enough to capture starter current draw
on some modern medium and large marine
diesel engines. If you frequently work with
such engines, you might want to invest in a
stand-alone amp clamp with a range up to
1,000 amps DC. (If you are not using the
inTELLECT EXP-1000’s clamp, select “not
available” during the initial test setup.)
First, the inTELLECT EXP-1000 verifies
the battery condition (described above in the
Battery Test section) as a prerequisite to any
starter circuit test. Once a good battery has
been confirmed, completing the test proce-
dure is simply a matter of starting the engine.
Use the same, simple two-wire positive and
negative connections at the battery already in
place and connect the optional amp clamp
around the battery negative cable.
With these in place, the inTELLECT EXP-
1000 will measure and record the following:

• average cranking voltage


• cranking amperage (if you use the
  optional amp clamp)


• cranking time in milliseconds


• starter loop resistance (in ohms); note
  that this test will only be useful if you

testing batteries, charging systems, and starter circuits 27

Decision Action

CRANKING NORMAL The starter voltage is normal and

the battery is fully charged.

LOW VOLTAGE The starter voltage is low and the

battery is fully charged.

CHARGE BATTERY The starter voltage is low and the

battery is discharged. Fully charge

the battery and repeat the starter

system test.

REPLACE BATTERY (If the battery test result was

REPLACE or BAD CELL.) The bat-

tery must be replaced before test-

ing the starter.

LOW CRANKING The starter voltage is high but the

AMPS cranking amps are low.

NO START The engine didn’t start and the test

was aborted.

CRANKING SKIPPED The EXP didn’t detect the vehicle’s

starting profile and skipped the

Starter Test.

Source:Midtronics

Starter System Decisions and

Recommendations

TABLE

2-2

Results of the cranking motor test, showing voltage, amps,
and cranking time. (With an attached amp clamp, this screen
would also display the starter loop resistance reading.)

The voltage reading during the cranking cycle.