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
    You should be able to check continuity by pushing the needle point probes of your meter in to the outside of the plugs for the connections that aline. If that doesn’t work then pull the plugs apart and see that they are visible clean dry and free from corrosion on the inside.

    You should be able to check continuity through the loom from the pin on a plug to the next connection (assuming you have a wiring diagram).

    I don’t know enough regards testing the reg/rec unit or alternator but if you remove the cover from the alternator it should look similar to the ones on eBay if alls well as in an even copper colour. If it’s defective you normally see a much darker brown or black area that’s burnt out and it smells like it’s cooked.

    Good luck
     
  2. MightyBoosh

    MightyBoosh Senior Member

    Mar 29, 2023
    514
    243
    Uk
    That thing in your hand is the reg/rec. The three yellow wires should all be carrying AC being generated by the stator which is the brown coppery thing referred to by @Boothman if you trace back to the connectors you will be getting AC across any two yellow wires as the generating is 3 phase. Not sure of the value but around 200v is common. Set your meter nice and high, 750 or 1000 volt range is normally available. That way you're covered safely. More accurately, your meter's covered :p Also, set your meter to DC volts 20v range and you can check if DC is coming from the black and red wires. That's going to your battery to keep it charged. :)
     
  3. MightyBoosh

    MightyBoosh Senior Member

    Mar 29, 2023
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    243
    Uk
    #63 MightyBoosh, Oct 14, 2025 at 3:18 PM
    Last edited: Oct 14, 2025 at 3:24 PM
    Most importantly, do you have an owner's manual? Haynes generally give all this info, along with resistance check you can do to further investigate the condition of the stator.
    Just had a bit of a Google, and the AC output could be as low as 18v, which surprised me a bit. Point being, it should be reading pretty much same voltage across any two of the three yellow wires.
     
  4. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
    Thank you all for your continued help with this issue I took the bike apart today and tested the stator across the 3 yellow wires in the connector block (photo below) which has continuity across all wires but was getting either a very low Reading or no Reading when testing the ohms but the coil itself looks okay so is it possible that the coil is knackered without being able to see the damage because I've heard when the rectifier/regulator goes it can take the stator with it damage there that I just can't see, also I do have the manual and the Haynes manual and it's supposed to be between 0.4 and 0.6 which is not just a clarify my above point and the inside of the wire connections look pretty clean too so I doubt is that either

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  5. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
     
  6. MightyBoosh

    MightyBoosh Senior Member

    Mar 29, 2023
    514
    243
    Uk
    Agreed mate, visually all looks good. Does that three pin connector have the yellow wires going into it? If so you can test the AC by starting the bike and reading across the alternator side of the wiring. Can run the bike with the alternator disconnected. Anyway, big bird for me shortly so l'll wish you luck and wait for your next report :)
     
  7. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
    Yes it did have 3 yellow wired from the regulator/rectifier but I disconnected it to test it, not sure how to test the ac side as there seems to be no wired to test unless that's under the air box where the stator wire leads to, also doesn't feel particularly safe starting the bike with that hanging off and I've had to drain the oil to get to the stator so probably wouldn't be very good for the bike either surely, but thanks for the ideas and enjoy your big bird :cool:

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  8. TRIPLE X

    TRIPLE X Senior Member

    Sep 1, 2021
    641
    243
    Norfolk
    So it's looking like it could be the reg/rec at fault and you need to test it. MOSFET seems to be a good aftermarket unit if you do need to replace it.
     
  9. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
    Thanks it's looking that way tho seeing as I didn't get the correct results when I tested the ohms on the stator lead then I'm thinking it's probably best to replace both does apparently they seem to go together, I found a mosfit regulator/ rectifier but it does not come with the stator though I did find this set on ebay with good reviews, not sure if anyone used one of these?
    https://www.ebay.co.uk/itm/12678864...6JBp8hBF3L59JBXroqOK7IZg==|tkp:Bk9SR8Cyofa8Zg
     
  10. Boothman

    Boothman Elite Member

    Jul 26, 2023
    979
    800
    Wigan
    I’d be tempted to contact this seller and double check is he selling both the alternator and reg/rec as the photo shows packaging for both dated 2020/2021 so genuine triumph and the last of the upgraded versions. The alternator has the longer lead allowing relocation of the reg/rec from its original warm location to somewhere with a bit more cooling flow.

    https://www.ebay.co.uk/itm/18616330...wwhbqwS3p2IG69nW1w93jj3I3W|tkp:Bk9SR5b8j_68Zg
     
  11. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
    Thanks again boothman that does seem like good value for original parts but they are so doesn't feel me with much confidence. I know my bike is far from you but I would expect any new part at this point will probably outlive my bike though I'm not sure I could say the same for I used part.
     
  12. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
    Thanks again boothman that does seem like good value for original parts but they are so doesn't feel me with much confidence. I know my bike is far from you but I would expect any new part at this point will probably outlive my bike though I'm not sure I could say the same for I used part.
    For the record I do think you right tho I'd rather go for something more legit than a random umbranded Chinese knock off, I might have to but a mosfit regulator/rectifier then buy an alternator/stator seperately
     
    • Agree Agree x 1
  13. Boothman

    Boothman Elite Member

    Jul 26, 2023
    979
    800
    Wigan
    They are down as used but it may just be they were never fitted. Try contacting the seller and find out the history etc
     
  14. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
    I have done this I'm waiting to hear back but as they are nearly the price of new ones I'd be more inclined to upgrade to mosfit or ultimate rectifier
     
    • Like Like x 1
  15. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
    I have to say with the stator looking so clean makes me wonder if I tested it correctly, all I did was took the 3 yellow wire connector apart and tested it across the pins in each combination with the battery connected and the ignotion off, is that correct cos I don't wanna replace it if it's working but also don't really wanna start the engine when it has no oil in it now to test it while it's on incase I wreck something else, Is there another way or is it worth me connecting my battery back up and testing again, I can get a decent upgraded mosfet rectifier seperare from the stator if I can make sure it works but I don't want to put it back together and fill it with oil again to be able to test it if I then might have to drain it and take it apart again if that makes sense
     
  16. TRIPLE X

    TRIPLE X Senior Member

    Sep 1, 2021
    641
    243
    Norfolk
    If the bike is upright on a centre stand or paddock stand it should not be necessary to drain the oil as the oil when static drains into the sump below. There should only be a small amount of residual oil that will drain out when you remove the cover.
     
  17. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
    #77 Tim - Sprint ST 1050, Oct 15, 2025 at 4:37 PM
    Last edited: Oct 15, 2025 at 4:48 PM
    Damn wish I knew that before I was following a Haynes manual :confounded: it mentioned about if it was on a side stand then to empty it so I thought better safe than sorry, I have reconnected the battery to test the stator connections again cos it looks too clean to be broke, do I need to wait for a while to let the coils in the stator charge or can I test it straight away? Also is it still OK to do this test while the stator is outside of its housing like this (it's still connected)

    Edit - I just ReConnected the battery and try to retesting but I'm still getting no result it is showing it has continuity but is Reading zero homes so and starting to wonder if i'm doing something wrong or maybe that this multimeter is just not good enough, because it is an automatic multimeter it looks like it is set to continuity and ohms when I connect the wires then it also has a k next to the logo so I'm guessing that I am looking for 0.004 to 0.006 maybe

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  18. MightyBoosh

    MightyBoosh Senior Member

    Mar 29, 2023
    514
    243
    Uk
    Those coils don't charge up. Imagine it as the reverse of an electric motor. Rather than power giving motion, motion (engine rotation) gives power. No point testing without engine running :)
     
  19. MightyBoosh

    MightyBoosh Senior Member

    Mar 29, 2023
    514
    243
    Uk
    BTW Electrex World are well rated for charging gear. If you wind up just needing reg/rec the R1 one is a popular upgrade
     
  20. Tim - Sprint ST 1050

    Sep 25, 2025
    19
    8
    England
    Great thanks as soon as I have ruled out whether or not the stator is working or not or whether I am just testing it wrong then I will place an order thanks
     
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