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HI every body ! I'm driving my Toyota Rav4 2007 when feell my steering going Hard and the break pedal doesn't working also . i just use the break Hand to stop and check what happen . when i lift the hood of the car i see the Positive lead was disconnected from the battery . when i connect it back all working fine .

My questions is : why the car doesn't continue working well as I know the alternator suppose to give enough power to drive once the car start ???馃檭
 

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There is likely a protection circuit built in to keep the alternator from frying all the electronics in the vehicle, a built in safety factor.
 

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There is likely a protection circuit built in to keep the alternator from frying all the electronics in the vehicle, a built in safety factor.
The alternator requires an external field voltage to excite the rotor. This is in all case of generation unless you are using permanent magnets as in a wind turbine.
 

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The alternator requires an external field voltage to excite the rotor. This is in all case of generation unless you are using permanent magnets as in a wind turbine.
thank you . it's mean i don't have to be worry it's not a mechanic problem
 

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It鈥檚 normal for this to occur...what I do wonder is why did the positive lead of your battery come off?
loll in the morning i remove the battery before leave home ,get it back and forget to tight the battery lead .
 

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My questions is : why the car doesn't continue working well as I know the alternator suppose to give enough power to drive once the car start ???
Yes, every car, once started, can run on the alternator only. The alternator provides the normal current to operate the car PLUS the current needed to charge the battery back after starting.
If that wasn't the case, then all the batteries would go dead while driving.
It's not very good because the battery smoothes any voltage spikes in the system that otherwise can damage electronic components.

PS: Another problem might appear when you try to run the car with a completely dead battery. Then the charging current is so large that it might damage the alternator.
That's why when you help somebody to jump-start their car you need to connect the cables with your engine off, and wait a few minutes. That way the current to charge the dead battery comes from you rown battery and not from the alternator. After those minutes, the dead battery got enough charge that, if you start the engine, won't damage your alternator.
 
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