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How to do a Alternator Replacement?

Discussion in 'Electrical' started by OhEmmBee, Sep 30, 2021.

  1. Sep 30, 2021 at 2:14 PM
    #1
    OhEmmBee

    OhEmmBee [OP] Rick

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    Hey I'm looking in the forums to see if there was any info on how to do a Alternator Replacement. Wasn't able to find anything besides what was on YouTube on a 07. Took my 18 Tundra SR5 Crewmax in today just yesterday to O'Reilly's to do a free battery, alternator and starter check. They determined after testing that the alternator is going out and needs replacement. Another thing is that my battery voltage gauge on my dash is kind of bouncing around. (Usually in the middle at 14v) and is looking like it's dipping to at least 13.8v. Right now my battery status, looking into my app that monitors my Tundra, is saying it's sitting at 12.4v now and 12.6v earlier.Screenshot_20210930-150431.jpgThis one below was another time after sleeping after getting home from work
    Screenshot_20210930-080309.jpg Addressing the elephant in the room, I'm not sure what alternator I would go with from O'Reilly's since they have 3 different options at 3 different technical specifications a load/amp ratings. And not sure if there is anyway to do this myself although I do want to get it fixed before it kills and drain the battery. Any help is great
     
  2. Sep 30, 2021 at 3:10 PM
    #2
    KingKong

    KingKong New Member

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    First off replacing the alternator on the tundra is the same from 2007-21, its the same chassis same frame just different body, that's why calling the 2014+ Tundras 3rd gens was always incorrect, and why they're now called 2.5 gens. So any YouTube vid or forum post will give you accurate information (and there are plenty out there). Second, you'll need at least the 150 amp, the 130 and 100 were for the 4.7/4.6 and 4.0 respectively IIRC. You can also do what I did and use a 180 amp alt from the Sequoia if you're in need of extra juice, or go with a Mechman, Stinger, or JS just to name a few if you are looking for headroom for lots of accessories or a bangin sound system. If you want stock capacity, go with a Denso reman, or better yet buy a brand new one. I personally would not go with an O'Reilly's reman, changing the alternator is such a f****** pain in the a** that if it goes bad you will be kicking yourself for having to go back in there again. Which brings me to my third point, this job is not for the faint of heart. Tundra owners call it the hardest easy job for a reason. If you want to do it yourself set aside a FULL day to do it, but it may take two. If I have to go back in there again I'm paying someone, don't care how much it costs.
     
  3. Oct 1, 2021 at 4:42 PM
    #3
    OhEmmBee

    OhEmmBee [OP] Rick

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    Got a link for any of the ones you just recommended? Planning to do a upgrade to support some more electrical devices. Refrigerated cooler, 4 or 5 pairs of off-road lights, upgraded sound system, e-lockers air compressor, winch. And maybe couple more fun stuff.
     
  4. Oct 1, 2021 at 6:12 PM
    #4
    Danimal86

    Danimal86 Looks clean even when its dirty!

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    Those monitors and remote starters will always have a load on your system.
     
  5. Oct 1, 2021 at 6:36 PM
    #5
    KingKong

    KingKong New Member

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    https://www.youtube.com/watch?v=7IC5KlzOLIY

    This guy breaks it down pretty well. I'd recommend at least a 240 amp if not higher with your planned mods. Never a bad idea to go more too, but I'd recommend doing the big 3 as well.
     
    OhEmmBee[QUOTED][OP] likes this.
  6. Oct 4, 2021 at 3:30 AM
    #6
    NueveTundra

    NueveTundra Mod list in Bio

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    Exterior: Toytec ultimate 3" lift level, Total Chaos Uniball UCA's, Total Chaos Cam Tab Gusset kit, AcanII smoked headlights, AcanII smoke Tail lights (2.5 gen style), DV8 front winch bumper , Badlands 12k winch with Apex Synthetic, White AUTMATCH Shackles 3/4" D Ring Shackle, Apex Winch shackle, Trail Ridge mirrors ,Icon Rebound Pro 17"x8.5" +25, Cooper Discovery STT Pro 285/70R17, PowerStop drilled n slotted rotors W/Carbon pads, Rigid flood flush mounts rear bumper , WeatherTec rain guards , OEM black side badges , Rigid Amber Radiance Pods. Energy Suspension Red Rack and Pinion Bushings, EAG front mesh Grille, RCI HighLift bed mounts. Rough Country DS2 Steps, A.R.E OverLand Canopy with Ascend basket, Stickers: ToyTec lifts windshield banner, Red Strange Music window sticker(back cab), White Strange Music sticker(back canopy), White Rigid sticker x2 (canopy sides), white Official BigFoot Research Team (Back Canopy) Interior: Alpine double din touch iLX-650 , JL C5-653's (front) JL C1-650x (rear) , JL JX400 4 channel amp , JL JX500 mono amp , 2 JL 12" subs , WeatherTec floor mats, Kenwood F/R Dash Cams, Black steering wheel emblem overlay, Tekonsha P3 Brake controller, ToyTec "Fresh" Scent coilover air freshener, Under the Hood: Koyo all aluminum radiator, Mishimoto red silicon hoses , XS Power 3000 amp battery , LAlectric 300 amp Alternator , K&N replacement filter. Online LED store accessories Fuse/relay box. (Identified) Dirty Deeds 8" Cat back exhaust with DD resonator delete/axel over converted into dump. Coming soon:
    I went With this guy right here Its been a great alternator so Far an feeds all my electrical demands very well. also was fairly easy on pocket witch was nice since I was spending a S**T Ton on other parts of my system. just know that If you go with Larger Amp than stock you will need to upgrade both the alt charging wire size and battery ground also at least 1 engine ground. a 300 amp alt would call for 0/1 (zero gauge) OFC wire.
    but changing the alternator is Fun its definitely a challenge for most people.
    07 TT 300amp alt.jpg
     
    OhEmmBee[OP] likes this.
  7. Oct 4, 2021 at 4:15 AM
    #7
    Danman34

    Danman34 New Member

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    13.8 running is 100% normal. These trucks are voltage regulated. Cold start you’ll see 14.0, Once warm, the alternator only puts out between 13.2-13.6 volts while running. There is nothing wrong with your alternator. Please do not listen to some guy behind the counter at OReillys. If the truck is starting fine. There is absolutely no reason to do anything. If it’s struggling to start. Change the battery.
     
    Last edited: Oct 4, 2021
    OhEmmBee[OP] and ljburns like this.

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