Schumacher PST-1000 - Manual (Page 5)

5
Figure 2
Connections For STARTER TEST
BATTERY
CHASSIS
BLACK
RED
KEY SWITCH
TRANSMISSION
SAFETY
SWITCH
STARTER
SOLENOID RELAY
+ +
-
DIAGNOSTIC TEST PROCEDURE
1.
Engine should be at normal operating temperature.
2. Hook-up the analyzer as described in the general instructions.
This includes having the load “OFF”, the Battery Clamps
connected to the battery, the Battery Volts checked and Amps
(reading) zeroed.
3. Perform starter test only with a good battery. Confirm the
condition of the battery by first conducting the Battery Load
Test Procedure as detailed earlier.
4. Make sure all lights and accessories are off and vehicle doors
are closed.
5. Place the Amp Probe around either of the engines battery
cables.
6. Set the Volts Selector to Battery Volts.
7. Disable the ignition by either disconnecting its power,
unplugging the coil primary, or grounding the coil secondary
wire.
8. Crank engine for 15 seconds (with ignition key and note the
cranking amperage reading. Also, watch to see that the
battery voltage stays above 9.6V. If a repeat of this test is
required, allow the starter motor several minutes to cool
before retesting.
TYPICAL STARTER CRANKING DRAW
ENGINE SIZE
Cubic Inches Liters Amperes
100 to 200 1.6 to 3.2 100 to 200
200 to 350 3.2 to 5.6 125 to 250
350 to 500 5.6 to 8.0 150 to 300
4. Switch Amps probe to 1000A position, Adjust Amp Meter to
read zero using the Zero Amps knob. Be sure the Amp Probe
jaws are clean and fully closed. (If Amps probe battery is
low, replace it with new one first.)
5. Place the Amp Probe around either analyzer Battery Cable.
6. Determine the battery load test amperes from the battery
test specification, CCA, or Ah ratings.
7. Turn the Load Control Knob clockwise until the amps reading
gradually reaches the required load. While the load is being
applied, watch the battery voltage. After 15 seconds at the
test amperage, or if the voltage goes below the minimum
value, (Table 2) turn the load off.
NOTE: The Time out lamp will light and the beeper will sound
after 15 seconds of the load testing.
8. Test Conclusion : If the battery voltage went below the
minimum voltage from the table during the test the battery is
either discharged or defective. Recharge and test again if
test results are marginal.
Note: MAINTENANCE FREE AND SEALED BATTERIES-can
be tested like any other ordinary battery except for the specific
gravity test. They have a sealed cover and carry a lifetime
supply of electrolyte. One type has the negative and positive
terminals on the top and another has them on the side. The
side terminal type have threaded terminal connections which
are sealed against corrosion where the cables are attached.
Freedom batteries may be charged or tested on-the-vehicle
using the existing terminals. However, when the battery is
out-of-the-vehicle, adapters for the side terminal models are
required.
Freedom batteries have an indicator built into the battery
cover. The color of this indicator verifies the gravity condition
of the battery.
EXAMPLE: Top side of battery:
• If the green ball is visible, the battery is charged.
• If the indicator is dark and the green ball is not visible,
the battery is partially discharged
• If the indicator is light yellow, the battery is low on fluid
and near the end of its useful life. DO NOT ATTEMPT
RECHARGING OR TESTING IF THE INDICATOR IS
YELLOW.
STARTER CRANKING TESTS
When testing the starting system, first test for battery performance.
With a known good battery, the starter motor, cables and starter
solenoid can be checked by doing the Diagnostic Test Proce-
dure.
The test procedure consists of cranking the engine for 15 sec-
onds while watching the starter draw amperage and the battery
voltage. Starter amps should not exceed the maximum specified
for the vehicle being tested, and the cranking RPM should be
satisfactory. Causes for engines failing the Starter Cranking Test
can be determined by using the following troubleshooting test
procedures. These tests pinpoint high resistance cable connec-
tions to the solenoid, switches and starter. High resistance can
cause slow cranking.
The starting system’s main electrical circuit is from the battery
POS (+) post, to a starter solenoid relay, to the starter motor, to
frame ground and back to the battery NEG (-) ground post. The
solenoid is controlled by the ignition switch and usually has a
transmission safety switch.
Corroded or loose terminals, broken switches and damaged
cables will cause voltage losses. Voltage drops (losses) are mea-
sured by connecting a voltmeter across the circuit parts and then
reading the voltage while the circuit is operated.
For all of these tests, the analyzer battery clamps must be
connected to the vehicle battery to power the voltmeter and
ammeter.
NOTE: Higher starter amps may be encountered if engine tem-
peratures are extremely hot or cold.
9. Test Conclusion: The system is good if the cranking speed
is satisfactory and the battery voltage stayed above 9.6 volts
If cranking speed was slow, use the following chart.