cranking system controll circuits Flashcards
cranking system control circuit allows the driver to use a
small current to control a large current flow to the cranking motor
the two main electromagnetic control switches in the starting system are
solenoid
mag switch
what makes a diagram easy to read in a schematic
when it has been broken out
when the ignition switch or start button are turned on it will send current to
the magnetic switch
when the mag switch is activated it will
closes its contacts and send signal current to the solenoid
what dose a solenoid on the starter do
moves the drive mechanism into mesh with the ring gear and closes contacts that will send current to the field windings
after the field windings have been energized by the solenoid
current then flows to the armature windings that will then drive the armature and drive mechanism starting the engine
what are connected in series with the mag switch circuit to protect the starter
safety switches
what will happen if the transmission is engaged when you try to turn on the starter
the starter will be overloaded and overheat very fast
what kind of safety switch is used on automatic and power shift transmissions
neutral safety switch
neutral safety switch are
normally closed and connected in series with the mag switch control circuit
trans needs to be in neutral to close the contacts allowing current to flow
mounting locations for the neutral safety switch
shift linkage
indicator panel
on the transmission
neutral safety switches are normally on what side the the control circuit
ground side
units with manual transmissions will use what for a safety switch
clutch position safety switch
clutch position safety switches are
normally open and are closed by depressing the clutch
are connected in series with mag switch control circuit
what side of the circuit will the ECU be connected into
the ground side of the mag switch control circuit
what conditions will the ECU monitor to prevent start up
potential theft
low oil level
trans in gear
low battery voltage
what is used to prevent overheating in the starter motor
the overcrank protection thermostat
the overcranking thermostat connections are normally
closed
overheating will cause the connections to open cutting current flow
how long should it take to close the contacts on a overcrank thermostat to return to closed position after over heat
1 to 6 min
where is the solenoid mounted
directly to the starter motor
what connects the solenoid to the drive motor
the shift lever
what two contacts are connected by the contact disc in the solenoid to allow the armature to start rotation
the battery terminal and the motor terminal
what is used to prevent the contact disc terminal damage when it is engaged
a cushion spring
what are the two types of windings in a solenoid
pull in
hold in
how is a electrical coil measured for strength
in amperturns
how are amperturns calculated
by multiplying amps by the number of turns in a winding
how is the pull in winding grounded
through the cranking motor
how is the hold in winding grounded
through the ground terminal
what happens to the starter motor when the ignition key is turned off
the starter turns into a generator and current will flow in the opposite direction
how is the current generated from the starter motor cancel when it is shut off and flows in the opposite direction
when it passes through the hold in and pull in windings in opposite directions and will cancel each other out
a mag switch is
a mechanical switch that operates electromagnetically
what condition is a mag switch normally in
normally open held there by a return spring
if a mag switch only has one coil connector
it will be used for power and the ground is supplied through the mag switch case
important thing to remember when replacing mag switchwes
that it has the same terminal connections and has the same power/amp rating
how should a mag switch be mounted
horizontally and 90 degrees to vehicle travel
what can happen to the mag switch if it is mounted improperly and it incounters road shock or impact
the contacts can close and starter will recive power
