Hey ladies and gentlemen Keith from iRepair Autos and today I'm going to show you
how to check your battery your alternator the voltage between the two
and once upon a time you'd have to use a voltmeter anyway I'm gonna show you how
to check that and if you ever go to your car put the key in the ignition to start
the car and you're greeted with a red warning battery message I'm going to
show you how to check that using a secret menu built into your Mercedes
clusters let's do with me hey but before we get started with this video if you
haven't please subscribe share and like this video it helps with the ratings on
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helpful thank you once inside the car put the key in the ignition put it all
over the position three right before you start the car you're not going to start
it though okay so the keys in position three the clusters showing the miles and
what we're going to do now is we're going to turn the key from position
three to position two then eight one two or three hit that reset button three
times once you've hit that reset button three times you're gonna see you'll be
and it should have twelve volts or higher that's the voltage coming from
your battery without the engine running you have a 12 volt battery your battery
should be telling you that it's 12 volts okay that indicates that your battery is
fully charged your battery's functioning properly now
once you're in this mode what you're gonna then do you're gonna start your
car but put your you know Canon the ignition key again and starting it once
you do that you're gonna then see a voltage climb up okay your battery is
now charging so the engine running it's registering thirteen point six thirteen
point seven volts so with your car running but not that kind of voltage
that's telling you that your alternator is now functioning if you started your
car and the voltage remain twelve volts that would mean that your alternator was
not putting out an adequate charge to charge your battery it has to be higher
than what the battery calls for so thirteen point five all the thirteen
point nine volts will adequately charge your battery if your battery was bad you
turned the ignition back off it would not register 12 volts like it
is now it would be much lower bad batteries can be as low as nine eleven
anything under 12 volts is a bad battery or a very weak battery that has not been
charged so that's how you do it ladies and gentlemen
no voltmeters no going under the seat to find your battery it's simple it's
clean and of course it's Mercedes nice as always everyone don't forget to Like
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drivers do-it-yourselfers can find them easier thanks and peace out