How to Replace an Alternator

How to Replace an Alternator


Hey guys
ChrisFix here
and today im going to show you how to replace a alternator
this is a really simple job that you can
do yourself in most cases there’s no
special tools and to figure out how easy
the job is going to be all you have to
do is locate your alternator in my truck
you can see the alternator is right at
the top which makes it really easy to
get to
if your alternator’s near the top of the
engine the job is going to be simple if
the alternator is buried it could be
more difficult if you’re not sure if
your alternator is bad i have a video
that shows you how to test an alternator
so check that out it’s really simple and
you could do it yourself a link to that
video will be in the description
here’s where my alternators having a
problem when the engine goes about four
thousand rpms the battery light comes on
and the voltmeter that’s built into my
truck
it just drops there should be 14.2 volts
will not even getting that I’m getting
like 10 volts nine volts once the RPM to
about four thousand rpms so not only is
the alternator shot but i’m running a
large light bar up top
some lights in the rear as well as off
road lights in the front so I want a
larger alternator to keep up with my
electrical demand stock alternators 95
amps and the new alternator is a hundred
and thirty amps and if you’re curious to
where I got this alternator I’ll go put
a link in description below as always
that pretty good prices and they got to
me really quickly so let’s go get
started and changing this out here all
the tools you need to do the job we have
a ratchet extension and different sized
sockets metal wire brush
flathead screwdriver and PCs and we have
a torque wrench breaker bar and the only
specialty tool that you don’t really
need but i have is this serpentine belt
tool that helps get the serpentine belt
off
you could always just use your breaker
bar or a long wrench
so let’s begin anytime you work on the
electrical system the first thing you
want to do especially when changing out
the alternator take off the negative
terminal on your battery
make sure it’s not getting grounded out
now you’re good to work on the
alternator
the next step is you need to access your
alternator
so try to make your life easier and make
as much room as possible we really don’t
want to take off this coolant hose
because then you get cool and everywhere
but what we can do is take off this
intake hose which is really easy to do
to get the intake hose off there is
a hose clamp right over here use a
flathead screwdriver
now we’re just going to disconnect this
hose that’s over here and just wiggle
this off
good we come over here to our mass air
flow sensor disconnect the little mass
air flow sensor electrical clip we could
just take this off just like that always
always remove your filters you don’t damage it
and look at that we have easy access
right here
now let’s go take the belt off to remove
the belt they do make a special tool
that helps remove belts
i’ll put a link in description to where
you can get it you don’t need to use
this it’s just like a long ratchet if
you have a breaker bar that’s kind of
narrow and skinny
you can use that or if you have a long
wrench in this case this is 15
millimeter and what you’re going to do
is going to go down into the pulleys and
look for the tensioner pulley so you can
see right down in here we go over here
the tensioner pulley is the
spring-loaded pulley right there and
that’s how you relieve the belt tension
to just go down in here
get the tool on the end of the bolt of
the tensioner and just take it and you
pull the ratchet the tool whatever you
have towards you and that pushes the
pulley against the tensioner spring so
you relieve the pressure and you can see
now the belt is nice and loose and since
we’re only taking off the alternator and
make your life a lot easier to just take
off the belt on the alternator and i’ll
leave the belt popped in here so it
doesn’t come apart and unwrapped from
around these pollies just in case if it
does you can see right here
it’s got the diagram of how the belts
rat around the police now let’s go take
the alternator off taking the alternator
off is really easy you can check your
brand-new alternator to see how many
bolted has you can see one two and then
one at the bottom is 3 so we’re going to
be looking for three bolts to take off
looking at this alternator
there’s one there’s two there’s three
so we’re good to go before we do that I
want to check the back of the alternator
see what connections you have here you
can see that there’s three connections
that this little one here got a larger
clip right here and we have the positive
cable coming
here I usually like to get these off
before I remove the alternator
especially since there’s plenty of room
to get to him back here so let’s go do
that
so the first cable we’re going to take
off is the red battery cable
this is the power from the alternator to
the battery runs all the way up over to
the battery
– 10 millimeter and you suck it over
that good
although our negative terminal is
technically disconnected just cover this
up so it doesn’t groundout
better to be safe than sorry you can
even get some black electrical tape if
you want but that’s good enough
ok now we’re going to remove this
connector and this connector flathead
screwdriver might help
that’s one
that’s too now if you remove this wiring
harness and move it up to the side
removing the actual alternator is really
easy we’ll start off with this front
bolt here
there’s three bolts total going to use a
breaker bar with these bolts are kind of
tough on here
the original alternator cars 2001 so
it’s pretty old
good broke that free will do the bolt
that’s up here broke that free and then
there’s one more bolt right back here
okay all three bolts are broken free now
we can loosen them up all the way it’s
one that’s two and three
now i can pull out the old one now what
the alternator out we have this
alternator bracket here and you just
want to get a piece of sandpaper or in
this case I have a metal wire brush and
just want to clean up the connection
where the alternator actually sits on
here because the alternator is grounded
to the block through this bracket so the
better the connection to the alternator
the better your electrical system will
perform
you also want to grab the bolts and
clean off the bolts you can see here
there’s all this white corrosion on the
threads here
you want to have a good connection so
it’s good to clean this off and that
cleaned up very nicely
so we’re going to get even better
connection now so with all the bolts
cleaned up and with the connections here
all cleaned up
let’s go put the new alternator on as
always when i’m installing two new parts
i like to put them side by side make
sure that they look right you can see
this alternator is definitely bigger but
the bracket mounting spots are the same
and the alternator pulley itself is the
same size so it looks like we are good
to go
and just for anybody who’s doing this
project on a Ford pickup truck or ford
SUV or the mazda pickup truck mazda SUV
the four hole pattern here indicates the
95 amp alternator and the two hole
pattern here indicates a hundred 30 amp
alternator just something good to know
especially if you’re looking for parts
in the junkyard
you’re trying to find this alternator in
the junkyard or something you know
that’s the 130 and then this is the 95
now we’re going to get our new
alternator put in place
one thing you might consider on these
bolts as anti-seize just put a little
bit on and using just a little bit of
anti-seize like that on the threads are
just make it that much easier to get off
if you ever need to replace this in the
future
now we’ll get our top bolt in you just
want to get it started
now we’re going to get the next to in
reason why you just want to get started
because you want to be able to move this
alternator around to make sure you get
the next bolt in its position and then
this last one should slide right in
just like so now with all three bolts
hand tightened and thread it in
we could start tightening them down you
don’t want to tighten them down all the
way
just get them snug and then we’ll talk
from them
so now that all these are snug
we’re going to get our torque wrench and
set it between 30 and 40 foot pounds i’m
doing thirty eight foot pounds 1 2
three now all we have to do is connect
these wires connect our intake here and
we’re ready to go for a test drive plug
that in love that in make sure you have
a good connection in here to use your
metal wire brush just to make sure it’s
clean or some sandpaper whatever you got
take the nut off slip the power cable
over the stud and hand-tighten good but
make sure you slide this protective boot
over that just feels at any water and
also prevents any unintentional
grounding or arking
good so we got our top connected
connected that middle one connected and
our power line connected make sure that
we have our plastic piece here over the
alternator
it’s just the heat shield that protects
the alternator from the excess heat now
we’re just going to get the belt on the
alternator and you see it doesn’t fit
until we pull this
good the belt is on here correctly on
the rest of the pulleys correctly now we
can take off our belt tool just inspect
to make sure that the belt is on all the
pulleys correctly it’s in the middle
it’s not on the edge plus the belt was a
little loose
looks good see if it’s right on perfect
everything looks good on the tensioner
now let’s put on the air intake and
let’s go for a rod drop our filter back
in place
this clicks in just like so you want to
make sure that this hose goes all the
way around your intake just like so
there’s no gap here now we can get our
flat head screwdriver to tighten this
down
good remember to connect our PCV hose
here
good make sure you plug in the mass air
flow sensor one last thing to do connect
our negative terminal and let’s go for a
ride
all right let’s start it up and see what
we get
so we’ve been driving around for a few
minutes and I’m gonna slow down here and give it gas
to drop a gear and hit over four
thousand rpms
beautiful everything is working
perfectly
and that is a job well done and that’s
how you properly replace an alternator
hopefully this video was helpful if it
was remember to give it a thumbs up if
you’re not a subscriber
what are you waiting for hit that
subscribe button up on the screen are
going to be a bunch of videos to get to
those videos you can click on the screen
or follow the links in the description

100 Replies to “How to Replace an Alternator”

  1. I had to change the alternator in my Saab 9-5 it was a complete nightmare I had to remove the inlet manifold the alternator right at the bottom of the car and you have to get it from the top of the engine i did get it in it took me 1 year

  2. @ChrisFix how has that Remy held up? I am needing to replace mine soon, I am having a slight whine. The Remy Is one of them I have considered.

  3. Hey Chris your belt looks like it was not alway on your tension pulley you might wanna check How your belt is tracking

  4. Good vid, unfortunately for me my car’s alternator is difficult to get to as it’s underside and in a front wheel drive car. Do u have a vid for a FWD car. I have replace a alternator on a 1970s era car with easy access

  5. A multi-bit screwdriver is my personal favorite for hose clamps. It has a 1/4" and 5/16' hex socket on either end, which fit the hex-head on hose clamps of all sizes, allowing you to turn the screw without risk of the driver slipping out. And of course, the removable bits give you two sizes philips and two of flat. Perfect for pulling miscellaneous parts at the junkyard.

    The gray and blue one sold by Harbor Freight is my favorite.

  6. Thanks again, between this job (just finished) and replacing my front calipers, breaks, and rotors, you have helped me save $400-600 in labor just in the past 45 days! 🙂

  7. for anyone doing this on a ranger or the mazda like chris, the 3 bolts that hold the alternator down are 1/2 inch.  Don't think that was mentioned in the video.  Did mine today with a wrecker part.

  8. Did a 2013 f150 5.0 yesterday… 2hrs and the need of two people to get the alternator off and on. Ridiculous. Any other alternator is 20 minutes top. Anyways, your video helped identify electrical connections. Couldn’t see them, but was able to feel for them and get them off

  9. Wil it really help the electrical system when upgrading big 3? I have a jeep compass and its crazy hard to get to the alternator. Do you think its worth it to upgrade?

  10. All I needed for mine was an 8mm wrench for the battery, 1/4" ratchet for engine cover, 3/8" ratchet for belt tensioner, and I believe it was a 10mm socket to take the alternator out of the engine valley.

  11. Hey, my friends scion xb started idling high after I replaced his alternator. Do you have any idea what that could be?

  12. couldnt help but smile at the end when it was a successful install and voltage didnt drop. I just purchased a 2007 Mazda 6 3.0 L wagon. new battery and oil change today, at the red light it wouldnt shift down from third gear and starts chugging so i pulled her off the road and she stalled. Got a boost and on my way home I get pulled over cause I was rolling threw stop signs due to the stuck transmission, she just clicks when I crank er over. guess im buying a new alternator. dashboard lit up like a christmas tree when i pulled off the highway…what a fuckin day…lol

  13. Brooooo who tf dislike a perfect video of this omgggg 🤦‍♂️🤦‍♂️🤦‍♂️🤦‍♂️

  14. Dude you are the straight up SH!*. Your attention to detail, yet never boring, easy understandable approach is priceless. As someone who has worked on cars all his life and watched his fair share of videos like this, yours is on another level my friend. And I could tell all those things just by watching this one video.

    You not only just got a subscriber in me, but you got a mouthpiece brother. I'm telling everyone I know that works on cars about your videos.

    Amazing job!

  15. I guess te problem caused by the regulator. You didnt have to change the alternator complately. I understood that you wanted to improve the charging capacity, so its okay but it would be nice if you work inside an alternator to make us learn 🙂 . I know that you are super busy with all these comments and everything, but if you seeing my comment i got a problem with my car. Last owner applied 3 types of silicon on the doors to stick the plastic trim, now i removed them and having a big trouble removing the silicone dirt. I tried everything to remove including wd-40, synthetic thinner etc. but couldn figure out how to remove them. If you could make a proper video to explain how to remove that silicone residue, it would be perfect ! Huge fan from Turkey !

  16. Recently i just learned how to put an alternator starter and fuel pump on the alternator and starter about the easier thing to do to

  17. is it ok to replace a 90 amp alternator with a 130amp? I need to replace my 120 one but am having a hard time finding one other than at the dealer?

  18. Thank you so much for your videos. I really enjoy it. Clear description and comments are encouraging me to do myself. Best Regards from Germany 😁

  19. Thanks Chris for helping me rebuild up my toolset every video you posted i purchase every tool set thanks

  20. Hey chris my 2012 mitsubishi galant sometimes like once every few months sounds kind of weird when i start it sometimes after it rains should i be worried

  21. Who else found it satisfying from the sound of him breaking those 3 bolts loose holding the alternator down?

  22. Hey Chris I just want to thank you for what you do with your help I was able to replace my alternator in my F150 with no problem. I did find out it was the alternator after watching one of your videos about testing the battery as well. You’ve just gotten another subscriber

  23. nice clip! since you have a larger alternator, is it OK to charger a battery set of (2X6V ) using
    solenoid or batt isolator? thanks

  24. I changed out the spark plugs on my F150 yesterday. Cranked it up and it was whining. Followed your video on testing an altenator, and that's definitely the culprit. Guess I'll be changing the altenator this weekend

  25. OOOPS chris you forgat to put a towel or something on the intake tube when you remove the filter! you usually don't make mistakes like that.

  26. In light of all the overweight and overly expensive trucks today, seeing u work on ur mazda makes me miss my 86 mazda b2000 std cab with its anemic 80hp four banger with 5sp manual. That was some reliable truck.

  27. This alternator in my dream car needs to be replaced! How's it going to be done? I need to see why. Here's why. (CLICK) Hey guys ChrisFix here!

  28. I have 2010 corolla with 1.8 engine and when I start the car the alternator show 14.0 volts and then i switch on the AC the voltage drops to 13.8 and with headlights it drops to 13.5 and after driving 15 min in hot weather the voltage drops to 13 volts at idle and 13.2 with 2000 rpm and at idle rpm drops from 850 to 750 rpm and if i on the full beam with headlights then voltage drops to 12.8 and rpm drops to 650, what do you think about the alternator ?? With full load and reving to 2000 rpm the alternator goes between 12.8 and 13 vole

  29. just did this today lol 2019. 2001 Ranger ….same truck …,.rip2001 to 2019 alternator……it dies a Legend! Original Alternator lasted this long…KUDOS lol Thanks Chris…I followed this vid and saved money! Thank You!

  30. They charge me $1100 to replace an alternator. Mechanics fuckin charge too much for this shit. I should've watched this video earlier so I can do it myself.

  31. Thank you for that me and dad replaced the camry alterneter and it sounds great and is little speed to it

  32. Your truck engine is almost the exact same as my 1997 Ford Explorer XLT. A lot of things are located in the same spot. I was having trouble with the air intake hose, but now know how to take it off. Thanks.

  33. Wish I could say it was this easy on my Mercury. It sits on the front right side way down on the bottom. Have to take the tire off, splash shield off, belt then the alternator shield. It’s easily a 2 hour job for me

  34. On a truck, yeah, this is a snap –I've done it. But I've got a Mitsibitsi and it's bustin my nutz! Lol Sorry if the language is too strong but it's meant in fun…

  35. Thank you Chris, just helped my friend with this on 2002 Ranger, followed your instructions and everything came out fine.

  36. Your one looks easy
    My alternator is right at the bottom of the car so will have to jack it up and get under the car which makes getting the belt off much harder

  37. Can i disconnect the battery and remove it safely and then go ahead remove the alternator so both parts can go get test.? Just curious for a safer route.

  38. Not to be a word nerd, Chris, but you say to take off the negative "terminal" of the battery at 1:48. One takes the battery "clamp" OFF the terminal, not the terminal itself. A terminal is a fixed part of the battery.

  39. My TSX turns on the battery light when I press on my brake. But every time I check it the amps are good. It always gives me 14.

  40. My car just all of a sudden just shut down. The lights and everything was on. But the motor just died. It would start up but just die out.

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