cranking system and testing service Flashcards
what should you before removing the starter
determine if the starter is actually faulty
what should be the first thing tested when trouble shooting
the battery group
how can batteries be more accurately tested
disconnected from each other
when testing batteries with studs or threaded holes
use adaptors to connect the test equipment to
if a battery has a hydrometer eye
green = 75% or above charge dark = less than 75% should be charged clear = replace battery
how should you charge a battery if the hydrometer eye is dark
at a rate of 15-25 amps for 15 min
how can you remove a surface charge from a battery with a carbon pile
by placing a 300 amp load for 15 sec and waiting one minute
how is a battery load or capacity test preformed
draw 1/2 the battery amps for 15 seconds and take a voltage reading quickly from the batteries loaded terminal and compare to a chart
what should not be over tight on the battery
the hold downs because they can distort the battery case
how can you mix the water and electrolyte after adding it to a battery
by charging it with 15-25 amps for 15 min
what is used to check specific gravity of a battery
hydrometer or refractometer
what should specific gravity readings from each cell be within to be balanced
.050 points
what should the specific gravity of a charged battery be
1.265 to 1.280 S.G
what dose a blue haze in a battery cell mean
that it has been shorted and needs to be replaced
how do you check voltage drops on battery cables without a carbon pile
by checking each section while the starter is cranking the engine
high current and low speed usually means
a mechanical resistance
can be from the engine or internally in the starter
low current and low speed can indicate
high electrical resistance
normally caused by loose or corroded connections
higher than normal current draw on the starter will cause the voltage drops to be
higher
lower than normal current draw on the starter will cause the voltage drops to be
appear normal
to test the solenoid contact condition
connect a voltmeter to the motor and battery terminals
what is the total allowable voltage drop on a solenoid
.2 volts
when the starter motor is cranking the engine battery voltage should not drop below
- 6 volts for a 12 volt system
19. 2 volts for a 24 volt system
what is the total voltage drop allowable for the cranking system
.7 volts ( .5 for the cables and .2 for the solenoid )
when using a carbon pile to test for voltage drops how much current should you draw through while testing
500 amps for a 12 volt system
250 amps for a 24 volt system
make sure not to test longer than 10 seconds
rapid in and out shifting of the cranking motor is called
solenoid chatter
when using a carbon pile to test the mag switch circuit you should draw how many amps through the system
100 amps for 12 volt system
60 amps for a 24 volt system
before removing the starter motor you should check the engine for free rotation by rotating it at least
two revolutions
if the no load test of the starter results in high current low speed the problems may be
short in the armature
mechanical resistance
ground fault
when cleaning the internal parts of a starter do not use
petroleum solvents
how would you test the over crank protection switch
with a heat gun
when testing the pull in windings do not exceed how long
8 seconds of testing time
high amperage during a winding test would indicate
a shorted condition
low amperage during a winding test would indicate
high resistance
what should your reading be if you hold your multi meter on the solenoid housing and one of the terminals
OL/OUCH
if the contact disc in the solenoid is not to badly damaged you can reuse by
turning over and rotating 180 degrees
what are some causes for solenoid chattering
low battery voltage
high electrical resistance
open solenoid hold-in winding
what conditions could cause the cranking motor to turn but the engine not to
broken armature shaft
slipping overrunning clutch
stripped pinion or ring gear
malfunctioning shift fork (or broken)
slow engine cranking is usually due to
low battery voltage
