Change Alternator Honda Pilot




About: I have always been tech support for just about everyone. I am an Autodidact. There is nothing I can't teach myself. I was a Auto Tech for more than 20 years. I was ASE Master certified. I was in the top 10 d...

I am assuming that you have done all of the preliminary testing to be certain your alternator is not working. For mine it was the battery that took out the alternator. The battery failed internally in such a way that would duplicate removing the battery while the vehicle was running. This spikes the charging system and blows the regulator. When it does this it shorts the charging system creating a large draw.

After some searching on the web I found lots of bad ways to do this job so I will show you how I did it. I have more than 25 years experience in the auto repair trade so I will show you young dogs how an old dog does this.

You are going to need some tools.

1 - Belt tensioner tool with the 14 mm crows foot attachment.

2 - 10 mm, 12 mm, 13 mm 14 mm sockets of any drive size and the appropriate ratchet. DO NOT use the 14 mm crows foot as a replacement for the 14 mm socket.

3 - Extension for the drive size you have selected.

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Step 1: Remove Positive Battery Terminal and Start Charging

First remove the negative battery terminal. This is a 10mm nut. Once loose pull it back over the plastic protection wall. Now remove the positive terminal. This was a good time to hook up the charger so I set it for a low/slow charge. If the battery is totally dead it is important that you slow charge otherwise you could cook the battery and warp a plate which will kill that affected cell.

When disconnecting the battery disconnect the negative first. This keeps the battery from making sparks that could ignite stray Hydrogen Sulfide coming from the battery.

Step 2: Remove the Beauty Covers

Remove the 4 - 10 mm bolts from the top cover. Set it aside, do not even try to fish out the bolts from the cover. Just leave them in the cover holes.

Now remove the second beauty cover. There is 2 plastic screw heads on it. Turn them 1/4 turn left (anti-clockwise) to release it.

When pulling the cover pull straight away from the valve cover. There is one small pin that goes into a grommet that we will be removing at a later step.

Step 3: Details, Details, Details

In this step we prep for the removal.

First remove the grommet that the second cover (from the previous step) went into.

Step 4: Remove the Power Steering Reservior

To remove the power steering reservoir you need to free the latch from the stand it is on. To do this gently pry the tab at the top of the stand and then put your hand under the reservoir and lift straight up. If it fights, rinse and repeat on this step until the reservoir is free.

Step 5: Remove the Coolant Bottle

Remove the cap from the reservoir. Take the time to note if there is any fluid in the reservoir. Now remove the reservoir using the same method you did with the power steering reservoir. Once you have it out set it aside in a place and way that it won't spill all over the place.

Take this time to remove the dip stick and make sure to set it in a place where it won't get debris on it. This is a step I skipped and found out later so my pictures will have the dip stick in place.

Step 6: Remove This Hidden Harness Hold Down

This is important and it is not something that you can readily see when you first look into the engine compartment. Actuate the latch and pull straight up like the reservoirs did and the harness will come loose.

Step 7: Remove the Serpentine Belt

You will need a serpentine belt tensioner tool with a 14 mm crows foot. Don't be a caveman and cheat; just use the right tool for the right job. I needed to give the tensioner pulley a nudge with a pry bar to get the serpentine belt tensioner tool on the nut.

Once you have the tool on the tensioner nut push the tool towards the firewall as far as the tool will allow and slip the belt off the pulley. On mine I slipped it off the smooth tensioner pulley first, then remove it from the alternator pulley.

Once the belt is off the pulley release the belt tool and remove it from the tensioner.

Step 8: Remove the Altenator Mounting Bolts

Here you will need a 13 mm and 14 mm socket.

Remove the upper 13 mm bolt then remove the lower 14 mm bolt.

I used my trusty super bad ass long handled ratchet with an extension and 14 mm swivel socket for the lower alt bolt.

Step 9: Disconnect the Alternator Wiring

You will have to twist the alternator so that the rear faces up to access the wiring. Remove the 12 mm nut for the battery wire and actuate the latch on the other terminal group (green) to release it.Battery

Step 10: Removing the Alternator

In this step you will have to be careful not to drop the old alternator in the car when pulling it as it may land on the AC line and rupture it. Like I said - use care. Finally we are able to remove the alternator. I twisted so it was pulley up and lifted until it stopped. Then I did an acrobat twist with it so it facing rear up and then wiggled it free.

Step 11: Quick Comparison Old V. New

I always take this time to check the part to make certain it is the right one. Set them up/down/and sideways next to each other. Make sure the terminals are in the same spot as well as the mounts and lastly make sure you have the right number of grooves in the pulley.

Step 12: Installing/ Getting the Alternator Into Place

I put mine in the reverse of my extraction. WITH MY HAND UNDER IT!! Pulley down and twisted as I went until it was in its final position. If this binds on the way in you will have to back up a step and try again after giving it a slight twist.

Before mounting it make sure to reinstall the battery terminals to the alternator

Now that we have the terminals in place slip the alternator into place and install the top bolt first. I did the top bolt first as it was the one I felt had the best access to start. Once you have it in a few threads you can let the alternator hang from the bolt.

Now install the bottom bolt and tighten both of these. Do not fully tighten these until both and snug enough to touch alternator mounts with no space between them and the engine side mounting. Once you are this far tighten them down. Don't be a gorilla; they don't have to be lug nut tight.

Step 13: Install the Belt

I installed the belt at this time as it would give me the most space to work with and allow me to see the alignment of the belt during install.

Slip your tensioner tool onto the pulley nut, check your belt to make sure it is on the bottom pulleys and pull up the slack in the belt. Now check the belt to make sure it is still on the pulleys. For mine I had to take a second pry bar to nudge the tensioner into position so I could put the tool on it. It was off by about 1/8 turn.

Now push the tensioner tool towards the firewall until it stops and slip the belt on the alternator. The temptation is to put the belt on the alternator first and then slip it over the tensioner. It may work for you but it did not work for me. I did not have enough throw with the tensioner tool to do it that way. So I put it on the alternator last.

Once it is on the pulley release the tool and check your work. Go back and correct any errors with the belt alignment now. If the belt is hanging off the pulley by one groove it will cut the edge of the belt and ruin it.

Step 14: Finish Up - Details Detail Details

This is the part where many 'shade tree' mechanics go wrong. It is the details that show that an amateur did the job. It is always these details that make it necessary to go back and redo part or all of the job.

Make sure to install the coolant bottle and the power steering reservoir back on their slide mounts. Now reinstall the loom hold down as shown in the picture. If you don't install this loom mount the tab could damage the upper radiator hose later on.

Step 15: Last Step - Hook Up the Battery

When connecting the battery connect the positive terminal first. This keeps the battery from making sparks that could ignite stray Hydrogen Sulfide coming from the battery.

I have intentionally installed the ground wrong in one picture. This is to show you how to not do it. Make sure the cables run over the lift handle. The hold down is not shown here because the battery was swapped before I got to the vehicle. Do not skip installing the battery hold down. Not using the hold down can shorten the life of the battery. While the well is deep enough to keep the battery where it is do not skip this last part.

Last but not least check the voltage with the vehicle running. It should read somewhere over 14.2 V.

Safe travels to you...................



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    12 Discussions


    8 weeks ago on Introduction

    Thank you SO MUCH for this instructional video. I have changed alternators on my vehicles before, but never on a Honda. When I first looked at where the alternator was, I was thinking that maybe I should have let the mechanic do it after all. Your video was super helpful and allowed me to do it myself and save over $500 on the repair. Great job!!


    8 months ago

    Thank you for this! It's always hard to find tutorials for cars (I've always hated video tutorials for this kind of thing.) Thanks for the help fixing my '07 Honda!


    1 year ago

    I just finished this job today on our Pilot (a 2012)... thanks for the detailed write-up and the pictures! The dealer wanted $900 to replace the alternator -- no way was I going to pay that much! The only auto parts store I found that had the necessary connector to test the alternator was O'Reilly auto parts. I tried AutoZone and Pep Boys and both were unable to test it.

    On the 2012 Pilot, there's next to ZERO clearance so the hardest part of the job was getting the old unit out and the new one in. Also, fitting the new unit into place took quite a lot of wiggling and trial and error but eventually it all went together nicely.


    1 year ago

    Is this for the 2005 Pilot bhy chance? Or is this same as the 05? I think mine is a 4 cylinder, or if they only used one engine, then its a 6 I guess(3.5L). Thanks! Excellent write up!


    2 years ago

    Thanks very much. Many good details. Just did the job yesterday after the alternator started smoking.

    I had to solve two problems.

    1. When installing the new alternator, the bushing in the lower bolt mount stuck out and would not go into the yoke. It would have fit if I had pushed it in first, but did not know. I had to remove the alternator to cuss at it, check clearances and push the alternator bushing to the center. Easy fit then.

    2. My aftermarket tensioner nut stripped removing the belt (nut was not quite 3/4") so I had to find another way to remount the belt. Fed the belt around everything and got the belt started on the bottom of the top pulley and used the 3/4 socket wrench to rotate the pulley and slowly feed the belt on to it.


    4 years ago

    Excellent write up. Inspired me to get cracking on my civic alternator!

    The Modifier

    4 years ago

    whohoa!! i'm a honda guy and i really love it!!!! ??


    4 years ago on Introduction

    I do like your detailed tutorial but I will still end up being that guy. If your are trying to teach the young dogs how to do things the right way then you must do things the right way. The right way to unhook a battery is to unhook the negative lead first then unhook the positive lead. The reason for doing so is so you don't accidentally short out the battery by hitting the frame with tools when unhooking it. To hook up the battery you always hook the positive side up first then the negitve.

    1 reply

    You are absolutely right. I missed that detail. Truth is that I have been lazy over the years and usually pull the positive first or whatever is accessible (see Audi). But the reason for unhookling and attaching the negative first is that it does not spark. In non-maintenance free batteries the vents readily give off Hydrogen Sulfide which is explosive. If one were to combine the spark from doing it wrong as you have indicated and the Hydrogen Sulfide you could have a potentially dangerous situation. I have updated the Instructable; thanks for your input.


    4 years ago

    or just simply let ur mechanic do the full detailed tutorial i dont have a honda but thanks this is so interesting and helpful


    4 years ago on Introduction

    I don't have the same vehicle, however, I love seeing full written tutorials for repairs like this. Very nicely done, sir.

    Thank you for sharing this!