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
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those videos you can click on the screen or follow the links in the description

42 thoughts on “How to Replace an Alternator

  • 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…

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

  • 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.

  • 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.

  • 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.

  • 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.

  • THANK YOU! fixed the alternator on my 2005 mustange
    going to start doing repairs my self now, WAY cheaper and I can impress my family lol

  • Great video thank you so!

    I have to change the alternator this weekend and my only concern is the alternator on the Scion it's located on the left side of the engine.

  • Thanks for your wonderful how-to videos!!I used this video to replace my alternator on my 2008 GMC Yukon Denali 6.2L, 203000 miles. Everything was going good but when I tried to lift out the old alternator, it wouldn't budge. The rusty "sleeves" in the mounting holes seemed to be stuck, I was perplexed. I searched another how-to video and found this helpful tip:To make the process of installing the new alternator easier… there are two sleeve inserts the two bolts go through, in the alternator mounting bracket. These sleeves move and can be easily moved a mm or two by a couple taps with a hammer, going from the engine side towards the bumper side. That pushes/slides each sleeve back a little and creates clearance for the new alternator to easily drop in. Tightening down the bolts again pushes these two sleeves back to a snug fit against the alternator body. [This allowed me to go ahead and PRY the old unit up and out without any further concern about the rusty sleeves.]Hope this helps anyone with a similar concern.

  • Hey Chris! Is this method universal on all models of cars? I'm still a bit of a car newbie, and I'm needing to replace my 97 Civic alternator and this was the only really good informative video I could find.

  • i have a 1994 pontiac trans sport and everything except one of the exhaust manifolds is out in the open. everything is so easy to access. why arent modern vehicles like this?

  • Perfect you save me a lot of ?, Mazda dealer in Clear Lake Houston charge $1,500.00 for replacing my alternator on my cx9, I really appreciate your video, keep up the good work ??

  • I had an alternator go out on me on my 2004 Ford F-150 on Labor Day. I picked up an exhaust tail pipe for my scrap run that was along side the roadway. I pulled in my upper driveway to put the tail pipe into my trailer and got back into my truck to move it and all my gauges went blank. The radio went off and to top it off I couldn't shift out of Park. I turned it off and tried to restart it and it wouldn't start so I jump started it and it started but wouldn't shift out of park. I shut it off again and then it wouldn't start. I called my brother and he had a big jump box we got it started again and leaving the jump box attached I could shift it out of park. The engine cut right out as soon as he took the jump box off so end of the story my alternator crapped out on me. I am thankful it happened in my driveway and not out on the roadway to where I would have had to call AAA for a tow. I went to the local junk yard and got one and slapped it in and it solved the problem. Advance Auto wanted $239 for the alternator. I got the one at the junk yard for $25 and it was under guarantee for 30 days

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