1. Welcome to Tundras.com!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tundra discussion topics
    • Transfer over your build thread from a different forum to this one
    • Communicate privately with other Tundra owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Tundra electrical gremlins

Discussion in '1st Gen Tundras (2000-2006)' started by SowalBeach, Oct 29, 2024 at 9:37 PM.

  1. Oct 29, 2024 at 9:37 PM
    #1
    SowalBeach

    SowalBeach [OP] New Member

    Joined:
    Tuesday
    Member:
    #125020
    Messages:
    6
    Gender:
    Male
    Vehicle:
    2003 Tundra 4.7L 4x4
    Recently replaced the 140A alternator fuse in my 03 Tundra because I was having intermittent start issues and the one that was in the vehicle was rigged up improperly (I’m assuming to avoid disassembly of the fuse box.) I had to bust the box apart a bit to get it open but shouldn’t have damaged anything internally. Auto parts store only had a 120A counterpart but I assumed it would work for the time being. After replacing the fuse, vehicle started fine but now no power to anything. Cluster, headlights, radio, turn signals, everything dead except for interior dome lights and hazards. Vehicle made it a couple of miles down the road and began to stutter and died. Now it won’t start at all. Had it towed to my home and put a brand new battery in it but still nothing. Won’t crank, only makes faint click when turning key. Not sure where to go from here. Ground next to the battery seems fine and I don’t see a good way to access the one on the engine itself. Wiring to alternator looks good. Checked every fuse both under hood and in cab.
     
  2. Oct 30, 2024 at 8:27 AM
    #2
    ATBAV8

    ATBAV8 New Member

    Joined:
    Dec 1, 2023
    Member:
    #107779
    Messages:
    475
    Tempe, AZ
    Vehicle:
    2003 V8 SR5, Access Cab, 4x4, White
    First things first. Do you have a volt meter? Have you confirmed you have good voltage at the battery?
     
  3. Oct 30, 2024 at 9:31 AM
    #3
    KNABORES

    KNABORES Sarcasm incoming

    Joined:
    Jan 1, 2020
    Member:
    #40572
    Messages:
    11,314
    Gender:
    Male
    Arkansas
    Vehicle:
    2000 Limited TRD AC 4X4 Thunder Grey 272k miles. 2019 Limited TRD CM 4x4 - SOLD
    Bilstein 5100's 16x8 589's with 265/75/16 and 1.25" spacers Flowmaster 50 series over the axle dump Pioneer touchscreen with backup camera Full interior and dash LED conversion Trailer brake controller with 7 pin Bedliner coat bumpers & trim ARE topper - Rhino Vortex rack
    Why was the original 140amp fuse blown and how did they rig it up without accessing the original fuse? Has it been running with the rigged up fix?
     
    ATBAV8 likes this.
  4. Oct 30, 2024 at 10:04 AM
    #4
    SowalBeach

    SowalBeach [OP] New Member

    Joined:
    Tuesday
    Member:
    #125020
    Messages:
    6
    Gender:
    Male
    Vehicle:
    2003 Tundra 4.7L 4x4
    Yes battery tests fine.
     
  5. Oct 30, 2024 at 10:07 AM
    #5
    SowalBeach

    SowalBeach [OP] New Member

    Joined:
    Tuesday
    Member:
    #125020
    Messages:
    6
    Gender:
    Male
    Vehicle:
    2003 Tundra 4.7L 4x4
    Not blown but it was rigged up with pigtails connected to the prongs of the previous fuse. Connections were corroded and looked like they had gotten pretty hot.

    IMG_0006.jpg
     
  6. Oct 30, 2024 at 10:11 AM
    #6
    KNABORES

    KNABORES Sarcasm incoming

    Joined:
    Jan 1, 2020
    Member:
    #40572
    Messages:
    11,314
    Gender:
    Male
    Arkansas
    Vehicle:
    2000 Limited TRD AC 4X4 Thunder Grey 272k miles. 2019 Limited TRD CM 4x4 - SOLD
    Bilstein 5100's 16x8 589's with 265/75/16 and 1.25" spacers Flowmaster 50 series over the axle dump Pioneer touchscreen with backup camera Full interior and dash LED conversion Trailer brake controller with 7 pin Bedliner coat bumpers & trim ARE topper - Rhino Vortex rack
    Pretty sure that female spade connector isn’t made for 140amp connections. If there is corrosion and signs of melting, need to clean all of that up and replace any corroded wires that won’t carry current and get it back to stock configuration. Check all power and ground wires for corrosion by cutting them back a couple inches from the connectors. The main battery to engine block ground runs from the battery down through a loom with a bundle of other wires and connects to the bottom of the block near the bell housing. Can be accessed from behind the drivers wheel underneath area.
     
    whodatschrome and shifty` like this.
  7. Oct 30, 2024 at 10:13 AM
    #7
    ATBAV8

    ATBAV8 New Member

    Joined:
    Dec 1, 2023
    Member:
    #107779
    Messages:
    475
    Tempe, AZ
    Vehicle:
    2003 V8 SR5, Access Cab, 4x4, White
    Hmmm. Sketchy. But, there's a reason someone did that shit.
     
    whodatschrome likes this.
  8. Oct 30, 2024 at 10:32 AM
    #8
    SowalBeach

    SowalBeach [OP] New Member

    Joined:
    Tuesday
    Member:
    #125020
    Messages:
    6
    Gender:
    Male
    Vehicle:
    2003 Tundra 4.7L 4x4
    Main ground to engine block looks fine. I replaced the rigged 140 with a 120 and installed it properly. It was right after that I lost all power and vehicle only cranks intermittently. At one point last night I could put the key in the ignition and get the door chime with interior lights working. As soon as I turned the key to start everything would go completely dead.

    IMG_0007.jpg
     
  9. Oct 30, 2024 at 10:43 AM
    #9
    ATBAV8

    ATBAV8 New Member

    Joined:
    Dec 1, 2023
    Member:
    #107779
    Messages:
    475
    Tempe, AZ
    Vehicle:
    2003 V8 SR5, Access Cab, 4x4, White
    I would go back to the original condition it was in when it was running. Not saying it's correct, but at least it would give you some sort of idea where the failure is. The intermittent start issues you had could have just been from the spade connectors. Not the best connection. It seems pretty clear there's no power going through the 120A fuse. Now to figure out why. Get it running and then go to some salvage yards to see if you can find a used fuse box?
     
    whodatschrome likes this.
  10. Oct 30, 2024 at 12:06 PM
    #10
    shifty`

    shifty` counting and breathing, disappearing in the fade

    Joined:
    Jun 20, 2020
    Member:
    #48239
    Messages:
    24,315
    ATL
    Vehicle:
    '06 AC Limited V8/4WD
    (see signature for truck info)
    What @KNABORES said.

    Also… Pull the 120A. Test continuity across the 120A. If you don’t have a multimeter test continuity LMK and I can share a cool life hack to validate fuses.

    Beyond that. What KNABORES said. Something is causing a short. To the point it got hot enough to short that wire originally. What does that mean? They hacked around the problem, you still have a short somewhere. Given the hackery elsewhere, I think you’re going to find, if you trace the wiring between battery and alternator, at the alternator harness, between battery and fuse/relay box, SOMEWHERE there will be evidence of pinch/short/hackery. A crimp that is loose. A bundle of electrical tape that melted away and is now arcing out. A wire that’s pinched. Something. Trace all your positive runs, look for bulges, bend them to look for stiff spots, you know the drill. But know, a lot of times it’s corrosion inside the cables on these trucks that causes issues that lead to shit melting down.

    Once you find your short - UNLESS your voltage regulator is fucked, which I would investigate!! - THEN start figuring out what else melted or which fusss popped.
     
    JasonC. likes this.
  11. Oct 30, 2024 at 9:25 PM
    #11
    SowalBeach

    SowalBeach [OP] New Member

    Joined:
    Tuesday
    Member:
    #125020
    Messages:
    6
    Gender:
    Male
    Vehicle:
    2003 Tundra 4.7L 4x4
    So get this shit. The terminal where the original 140 was rigged is not even the correct terminal. If you look at the picture I posted previously, it’s in fact supposed to be the terminal above where it was installed. How it ended up in the wrong place or even worked at all is beyond me but at least I’ve solved the problem. 120A fuse seems to be doing just fine but I ordered a 140 to keep in the glove box in case it gives me problems down the road. Thanks to everyone who weighed in on this one!
     
    shifty`, KNABORES and w666 like this.
  12. Oct 31, 2024 at 4:45 AM
    #12
    KNABORES

    KNABORES Sarcasm incoming

    Joined:
    Jan 1, 2020
    Member:
    #40572
    Messages:
    11,314
    Gender:
    Male
    Arkansas
    Vehicle:
    2000 Limited TRD AC 4X4 Thunder Grey 272k miles. 2019 Limited TRD CM 4x4 - SOLD
    Bilstein 5100's 16x8 589's with 265/75/16 and 1.25" spacers Flowmaster 50 series over the axle dump Pioneer touchscreen with backup camera Full interior and dash LED conversion Trailer brake controller with 7 pin Bedliner coat bumpers & trim ARE topper - Rhino Vortex rack
    Im not sure that your problem is truly solved. I bet there are shenanigans beneath that fuse box. If it works now and that’s enough, then good deal.
     
  13. Nov 1, 2024 at 11:00 AM
    #13
    SowalBeach

    SowalBeach [OP] New Member

    Joined:
    Tuesday
    Member:
    #125020
    Messages:
    6
    Gender:
    Male
    Vehicle:
    2003 Tundra 4.7L 4x4
    Well you called it KNABORES. Got the fuse situation straightened out Wed. afternoon. Drove the truck for the remainder of the day and all day yesterday with zero issues of any kind. Drove it to the store this morning and when I went to leave had no power whatsoever. Hooked up my jump pack and it fired right off, however when I disconnected the jump pack it died immediately. Disconnected and reconnected the battery and it fired right up as if nothing was ever wrong. Ive cranked it about a half dozen times since and no issue. Just to recap, I have a brand new battery that tests fine. Ive checked my grounds and they look fine as well. All the wiring that I can access without tearing anything apart also looks good. 120A fuse that I replaced the 140 with also still in good shape. Seems like it's almost certainly a short somewhere, but I'm running low on ideas.
     
  14. Nov 1, 2024 at 11:49 AM
    #14
    shifty`

    shifty` counting and breathing, disappearing in the fade

    Joined:
    Jun 20, 2020
    Member:
    #48239
    Messages:
    24,315
    ATL
    Vehicle:
    '06 AC Limited V8/4WD
    (see signature for truck info)
    Have you looked at the underside of the fusebox? It'd a bitch to pop it up, and one part physically pops down out of the hole (we can help if you give pics of your fusebox, maybe)

    Here's why I mention it, this guy was having 'bad alternator/charging problems: https://www.tundras.com/threads/charging-alternator-problems.97131/#post-2469357

    But beyond that, here's why @KNABORES is mentioning corrosion in the cables: https://www.tundras.com/threads/1st-gen-psa-clean-your-battery-terminals-you-lazy-sods.131635/

    Oh and I remember this guy also who had a taped up short from a previous owner on the positive line up under the truck, which lost or melted some tape and was arc'ing to the frame, here: https://www.tundras.com/threads/2003-sequoia-electrical-problem.124410/#post-3186960

    I am suspicious you're going to find something stupid on the line from the battery to the alternator like that guy, and first thing I'd be doing is tracing the wire between the positive batt terminal and the alternator. If you don't see anything bulging/out of place/taped unlike other areas down the loom, and you have a multimeter, I'd be testing that wire run for resistance to see if it's fucked up. Also, there's easier access to the wire harness bolted to the alternator if you go thru the passenger wheel well, pop off the round clips for the splash guard. Pop it off, look for damage or meltdown. See if the truck will run on a fresh battery with that cable disconnected (I think it should?) which could potentially tell you whether or not that's the line causing beef.
     

Products Discussed in

To Top