welcome to another episode guys you know
I've had a lot of questions regarding
the neutral safety switch or the
inhibitor switch and how do you in fact
test the switch itself I do have a video
uploaded showing how to replace the
switch but when I shot that it was
during the winter time there was snow on
the ground and I just didn't have enough
time to go ahead and test or show you
how to test the sensor itself but today
I will show that we'll go ahead and go
through how you can test the the
inhibitor switch and all that you need
is a multimeter and essentially what
we'll be doing is looking to see if we
have continuity continuity just means
that there's an electrical connection
between two points if we don't have any
continuity then there's a break
somewhere in that connection and you
need to replace the sensor so that being
said let's go ahead and let's begin all
right now the neutral safety switch is
located toward the bottom
it's toward the front of the vehicle
this happens to be a Nissan Maxima in
1887 but on this vehicle is toward the
bottom on the driver's side last time I
shot this video that was snow on the
ground and this is the way that I got to
it however today we have the car in the
garage and it is quicker if you obtain
or get access to the switch right here
now this is a plastic cover and you have
a couple of screws holding it on so I'm
going to remove this cover and we'll
have quick access to the sensor now once
you remove that plastic tab this is what
you're going to see this happens to be
the transmission and right in the front
right here this is the inhibitor switch
and of course you have a this is the
gear selector so in fact when you change
when you put the vehicle from reverse to
neutral to drive this whole system this
whole lever is moving and the sensor
really the whole point about this sensor
is to make sure that the car doesn't
crank while it's in Reverse or drive or
drive it will only allow the
car to crank and park in neutral so if
this sensor starts to go your car may
not crank at all because the sensor has
no idea what gear you're in or the
sensor thinks you're in a reverse or
forward gear so what I'm going to do
I'll clean up the top of the motor
because there are two electrical
harnesses and they lead up toward the
engine bay and there's so much clutter
up there that you won't clearly see what
we have to do so I'll clean up the top
in fact if you're curious what I'm doing
just take a look I'll include a link
right now for the first video that I've
uploaded and I show in detail how to
clear at the whole top of the engine if
you're curious but anyway I'll clear at
the top we'll have clear access to these
harnesses and then we can go ahead and
start the testing okay so everything is
cleaned out here if you take a look
these are the two harnesses that lead to
the sensor there's your sensor right
down there so let's go ahead and unplug
these two sensors these harnesses OOP
sorry about that we're going to unplug
these two harnesses right here and then
let's do the continuity testing so you
press down the tab here and these things
keep it really tight just enough force
there you go since your first one you
have another one right here and there
you go so now we need to check or do our
testing from these terminals because of
course these harnesses lead to the
sensor this goes toward the computer of
the vehicle we're not concerned about
this right now we just want to make sure
that the sensor is okay now once you
disconnect those two harnesses go ahead
and also disconnect the shift boot
leading to the sensor and I'll show you
in a minute why does it really want to
do this but just go ahead
and remove this right from the sensor
okay now this is free and clear and I'll
show you why you really need to do that
the next step is we need the multimeter
specifically we need the ohm setting now
if you've never used a multimeter
they're pretty simple to use in this
case again we need the ohm setting let
me just get my leads a free here so as
you can see we have a black and a red
wire and you have three inputs in this
case so in this case we have the black
wire going to the black input and then
you have red wire which would either go
to the 10 amp or you have volts ohms and
milliamps in this case since we're doing
ohms we lead it to that input all right
so again we need the ohm setting and we
need the audible this audible selection
here as you can see it gives you that
this marking letting you know that
you're on that you are on a an audible
setting so if you cross a batteries a
little low here but the cross is two
leads here you have an audible alarm
letting you know that you've completed a
circuit or you have continuity in other
words so that's what we need to test on
these harnesses so let's go ahead and do
that so let's go ahead and zoom in here
let's start with this first one this
only has two leads coming out out of
this harness and just go ahead make a
connection let me just make sure you
guys can see this make your connection
and we should have continuity which we
do as you can hear so this harness is in
good shape it's working correctly
now for the second harness this is a
little bit more involved first step is
we need to make sure that the inhibitor
switches in the
position so I'll include a picture right
now and on the upper right hand side of
the screen to showing that the inhibitor
switch is in the park position then what
we need to do is check terminals three
and four now that happens to be the top
left and the bottom left on this vehicle
now really to do this test obtain the
factory repair manual for your vehicle
because every card is different you can
do this by trial and error but really
get the repair manual for your car just
because you can essentially do any
repair and including this one so we'll
do terminal three and terminal four and
we have continuity now another way you
can test this if you don't have a
factory repair manual you could do trial
and error in other words let's say I
have no idea which two points to touch
if I just start going along here you
don't hear anything at all and that's
because only two points make continuity
in the park position okay so these two
points not a this point nothing this
point nothing but when I get to the
bottom there is continuity so I know
that this happens to be for park so this
is working correctly now the next step
is to check the reverse position so
we'll remove the excuse me we'll move
the inhibitor switch to the reverse
position and then we'll check terminals
three and terminals five park into
reverse all right so we're in the
reverse position so Terminal three is
always on the upper left here on this
vehicle and Terminal five happens to be
on the bottom as well so here we go and
we have continuity again if you touch
anything else you won't hear anything
but if you touch Terminal three in this
case and Terminal five it works so
continue to do this test through neutral
Drive second first gear and see if we
gain continuity throughout all gears and
you should now one other thing you could
do is reattach
the control cable back onto the sensor
and then check for continuity and you
want to make sure they still have
continuity once that control cable is
reattached to the sensor then get on the
vehicle put the vehicle into reverse and
check for continuity and then get back
in the car put the car put the gear
lever into neutral and then check for
continuity and so forth and do that
throughout the gears this is just a
safety check to make sure that that the
control cable is properly adjusted now
if you're not getting continuity here
then go ahead and just adjust the the
control cable now one more thing before
we wrap this up this is in regards to
sometimes if you try to crank the car or
start your car and nothing happens in
Park and if you shift it into neutral
and the car cranks sometimes you just
need an adjustment and in other words
you want to make sure that that this
lever or this lever here is in alignment
with the sensor now to do that it's
pretty simple what you want to do let me
just get a ratchet here first you just
need to loosen up the three nuts holding
on the sensor here so just loosen them
up these happen to be a 5/16 of an inch
and there's another one oh you got put
this in neutral okay make sure it's in
neutral right here just watch your
fingers all right that's good enough now
what you need to do is I'm going to use
a an allen key if you have a pin that
will also work on top here you just
place a pen or a nail and key and you
want to make a contact book you want to
make contact with this other lever right
here
and this essentially aligns everything
so
when you start the car the vehicle knows
that you really are in park and it will
allow you to start the vehicle if these
two points are off sometimes you have to
shake the the the transmission lever and
then the car will crack and that's just
because these two points are not exactly
in sync with each other so just go ahead
and also check this as well and then
what I like to do is we'll keep this the
pain or allen wrench or allen key
whatever you're using keep it in place
and just tighten everything back down