Need Help Identifying Loose Tubes

Discussion in 'Technical Help' started by Tim - Sprint ST 1050, Sep 25, 2025.

  1. Boothman

    Boothman Elite Member

    Jul 26, 2023
    979
    800
    Wigan
    Could be a bad connection between the regulator/rectifier arrangement and battery if you are lucky
     
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  2. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    I'll be honest I have no idea what either of those are but the battery connections were solid and so were all parts they were connected to that I could see including the little box next to the battery if that's what it is, (electrics is not my strong point unfortunately) hopefully I'll have more info if I can find my multimeter to morrow but I'll keep you posted :blush:
     
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  3. Boothman

    Boothman Elite Member

    Jul 26, 2023
    979
    800
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    What year is your bike
     
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  4. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    It's a 2006 also I have now ordered a new multimeter so I should have it delivered tomorrow
     
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  5. Boothman

    Boothman Elite Member

    Jul 26, 2023
    979
    800
    Wigan
    #45 Boothman, Oct 9, 2025
    Last edited: Oct 9, 2025
    So this may help
    https://www.fowlersparts.co.uk/parts/6799/sprint-st-1050-from-vin-208167-/starter-alternator
    could be item 7 or item 2. Check the plug connectors are all clean and dry. If it’s 2 you can usually see an issue - everything should be an even copper colour, but when they go it’ll smell and look burnt.

    Not available from Triumph anymore by the looks of it but a quick search on eBay turns up pattern parts like….
    https://www.ebay.co.uk/itm/315653962120?_skw=t1300111&itmmeta=01K75JXM6K6849BTQ37J1JM9QR&hash=item497e713988:gBwAAOSwNSVmtycq&itmprp=enc:AQAKAAAA4FkggFvd1GGDu0w3yXCmi1eZr8W4RHwjeI/OQXk75aRDYrf9UzKNqCqmjuFX4/7wxJCwjapQDK07i20+PK5PjHFTr8E2ZCY8IZ8ZGsALYL18sFrvNM8SjOVRLzy09ehZZm5wTzVb/SWA+SL1eFFwoyXV9201o3t23c/+BfgGvAaLrr/sbr8hueP/8Tym8tnP00iJs8R+3uPOV5iCNN8jnU4IgL3lnJ66JutoOdItBAQmdBxQ1291OMpydWs4F0uSNc4pYxkrNdSjjLo0+j0NswuLxlnPr4Mq8VUQLPN0UIEZ|tkp:BFBMwMP2srlm
     
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  6. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    Ahh great thankyou that will help massively :blush:
     
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  7. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    I received my new dummy proof multimeter today and tested the battery, first pic is just after I took it off trickle charge 13.38v then I turned the bike on and got the second pic 12.49v then I waited till the bike warmed up for a few minutes and again got 12.49v and a minute or so later I got 12.44 then I done the test whilst reving which I took a video of, link is below

    https://youtube.com/shorts/Giy9wdNP0Iw?si=YBjJtpIvIQbt-fs4

    Then I turned the bike off and took a video of what was happening which also shows the battery, that video is below (just to say the part next to the battery was seated properly and did have a cover over it but I took it out so I could see the fuse which looks ok)

    https://youtube.com/shorts/1tWmjrOdWBw?si=OauOCRIFlsmDtLUT

    Then the last 3 pics I took (about every minute of so) were of what was happening to the voltage while the bike was off and cooling down then the last one with the screen illuminated was after 15minutes.

    From what you guys have said it looks like the voltage is climbing even while off which confuses the hell out of me

    I hope this makes sense to someone but if there is anything I messed out which may help let me know please

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  8. TRIPLE X

    TRIPLE X Senior Member

    Sep 1, 2021
    641
    243
    Norfolk
    When you take the battery off the charger you should wait about 30 minutes before checking the voltage or you will get a false reading. It looks like the bike is not charging the battery so you need to check the alternator and the regulator/rectifier. I would first remove the alternator cover to see if there is any evidence of burnt windings. You need to consult a workshop manual or the Internet to see how to check the electrical components. The reg/rec seems to have been an issue on early models like yours as it was badly located and it was moved to a new location on later models. It gets hot and has a finned heat sink which ideally needs to be in the air flow to keep it cool. A Mosfet aftermarket replacement reg/rec seems to have been a common choice.
     
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  9. Boothman

    Boothman Elite Member

    Jul 26, 2023
    979
    800
    Wigan
    Good info and the minor fluctuations after being turned off could just be temperature related. The main thing for me is when you reved the bike the voltage dropped significantly which (and I’m no electrician) points to no charge coming from the engine.
    You could take a picture of what’s happening at tick over, go for a 10 minute ride round back to your house and then take another photo of what’s happening on tick over to see how much the voltage has dropped after the battery has been running under load for that time.
    With the ignition turned off have you checked the plug connections on the regulator and rectifier to ensure they are clean, dry (with no sign of corrosion) in general good order and fully seated giving electrical continuity across each wire?
     
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  10. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    No to be honest it wasn't till you sent me that exploded diagram that I even knew what one was but Unfortunately I'm staying away for a few days now so don't have access to do any more tests yet so I'll do some research on where it is and check the connections and hopefully a guide on how to test it, also to be honest I don't think I'd wanna take it out again after being stranded twice, I don't have the space around my house and the owner of the van that was used to recover it has gone on holiday so too risky

    Would it be ok (because I left the trickle charger off) if the voltage was tested tomorrow as that would be over 30 mins or does it need to be closer to the 30 mins mark so the voltage does not drop too low?

    Also is this something that a diagnostic machine would pick up because If that can do tell me what's wrong it might be worth me trying to find one, I know I bought a Bluetooth one for my car and told me all sorts of info
     
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  11. TRIPLE X

    TRIPLE X Senior Member

    Sep 1, 2021
    641
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    Norfolk
    I would expect a good fully charged battery to be at least 12.6v after standing for about a day but 12.8v would be better. The alternator produces AC which is then converted to DC by the rectifier to power the electrics and charge the battery. The regulator prevents the battery from being overcharged. The rectifier and regulator is combined into one unit.
     
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  12. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    Ahh ok I'll see if I can got hold of a reading tomorrow of what the battery is sitting at after being left off charge for a day just for the extra date till I can get back to it and will look into the alternator, rectifier, and regulator thanks
     
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  13. TRIPLE X

    TRIPLE X Senior Member

    Sep 1, 2021
    641
    243
    Norfolk
    I take it the MIL light is on indicating a fault? Unless you want a diagnostic tool for the future it will probably not give you much more information at this stage as the fault seems to have been narrowed down to 2 components which need to be tested. Dealertool is good and reasonably priced if you do decide to get diagnostics but needs to be plugged into a laptop with windows operating system.
     
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  14. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    To be honest I can't remember which lights came on but I believe I took a video earlier in this chat which showed me attempting to start the bike and it is doing the same thing but once the bike is charged using my battery charger then it runs fine and does not come up with any lights until it fails again but thank you for the extra info I will check out the diagnostic tool that you mentioned but I agree I think it may be a little early if it has been narrowed down to one of those two parts then testing that will probably give me more information than the diagnostic will
     
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  15. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    Hey guys I have just redone the tests after still not being on trickle charge since my last test on friday and the results were
    13.13v before starting
    12.35v after starting whilst still cold
    12.30v after warmed up then the video shows me reving the bike and it cut out while I was filming then I took a picture of the dash after the bike had cut out (apologies for the talking in the vid I had someone help record to make sure I could film and hold multimeter secure whilst reving)

    https://youtube.com/shorts/WR3N7UiL3j4?si=hxos9mi_M45EgJ_e

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  16. MightyBoosh

    MightyBoosh Senior Member

    Mar 29, 2023
    515
    243
    Uk
    That looks like it's not charging. You'd do better to increase rpm and hold a steady engine speed rather than blipping the throttle like that. Around 3k rpm for 10 seconds or so, see what voltage it gives
     
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  17. Boothman

    Boothman Elite Member

    Jul 26, 2023
    979
    800
    Wigan
    Before you start replacing parts - as we are relatively agreed the bike isn’t charging the battery have you tried what I suggested previously……..

    With the ignition turned off have you checked the plug connections on the regulator and rectifier to ensure they are clean, dry (with no sign of corrosion) in general good order and fully seated giving electrical continuity across each wire?

    A bad connection is cheaper to fix than buying new Reg/Rect etc
     
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  18. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    #58 Tim - Sprint ST 1050, Oct 14, 2025 at 12:43 PM
    Last edited: Oct 14, 2025 at 1:09 PM
    No sorry I have only just got back so I havnt had a chance to take it apart yet but that will be my next priority thankyou

    Edit - I have just found where it is on the bike but I need to take the faring off to check it so will do that tomorrow, thankyou for reminding me
     
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  19. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    Hey Boothman I managed to take the fairing off and took a few quick pics but looks ok tho the connections are dirty they are solid and clean on the inside, not sure where I would need to place the multimeter to do a continuity test

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  20. Tim - Sprint ST 1050

    Sep 25, 2025
    24
    8
    England
    OK so I think the main question now is, is there a way to test the stator/alternator (seems like the same part from most of the diagrams) and same for the regulator/rectifier or am I better off replacing both to be safe, in which case is there a preferred aftermarket one because i have found many on eBay but they seem a bit too cheap to be trusted
     
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