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Help: Nations and Mechman Alternator Issue

Discussion in 'Engine/Tuning' started by TRBO VNM, May 13, 2016.

  1. TRBO VNM

    TRBO VNM Authorized Vendor Authorized Vendor

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    I need some help here. Really getting frustrated and pissed off. Friends/customers spending good money on these alternators and having issues.

    I have already contacted Nations about one persons and they have no answers. Now at least 1 mechman is doing this. I have seen it posted on here, but the search function hasn't been working for me lately.

    Basically, all voltages are great, but in higher rpm the battery light flashes. Logs show battery voltage being over 13.5 and generally closer to 14.0 through whole run.

    The mechman I just did I used 4 gauge power from the distribution box to the alternator and I did a 4 gauge ground from the battery to the case of the alternator just like the instructions said. I have the factory 8 gauge wire still connected to the distribution box because of the signal wire since they are tied into the same ring terminal and I covered up the other end of the 8 gauge wire so it wouldn't short out. You might ask why not just connect it to the alt...well, the damn stud is a different size and the factory ring terminal is smaller. So why not just put a different ring terminal on you say? Because you can't orientate both terminals cleanly. If keeping the factory 8 gauge power wire on it will fix the situation I will figure out what to do to make that happen, but nations said that should not cause an issue because the battery light is based on the signal wire, not the large gauge power wire.

    I have another mechman I installed that will be tuned tomorrow. The difference with it is that I have 0 gauge going from the distribution block to the alternator and the same gauge wire from negative terminal on the battery to the alternator case. The only thing I didn't do with this that they recommend is the 0 gauge going from battery to the frame and fender. You just can't do that with these setups. I can do one of those, but not both. The wire is so damn big there is no room for it all and no battery terminal I have seen to accept 3, 0 gauge wires.

    So I am wondering those of you with these alternators with no battery light ever, how are you wiring them up? Nations and Mechman said I have done everything right.
     
    Last edited: May 13, 2016
  2. 96gt02

    96gt02 Well-Known Member Established Member

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    Interesting, ive seen a few thread about this popping up a lot recently, wonder what the issue is.
     
  3. TRBO VNM

    TRBO VNM Authorized Vendor Authorized Vendor

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    Not sure, but it's pissing me off. These things aren't cheap and people should not be having this issue. If there is something else I can do on the install I will, but so far both have told me the install is fine. We even sent the nations back for testing and they said it checked out fine.
     
  4. keith89

    keith89 Well-Known Member Established Member

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    I'm having the same issue with my mechman but after datalogging, it does not seem to be a major issue. It is holding 13.5-14v through a WOT pull but the battery light flickers on occasionally. That makes me think its the voltage signal to the ECU from the alternator. I just read an older post where someone found that the pigtail that came with the alternator has loose pins that may not be making contact. This sounds like a potential cause of the flickering battery light even though the alternator is putting out the correct voltage. I'll have to try securing the pigtail better and see if that fixes it.
     
  5. TRBO VNM

    TRBO VNM Authorized Vendor Authorized Vendor

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    Ok, thank you. I will look as well, but odd that right now it is 2 different brand alternators doing it on 2 different cars. I think the pigtail is different as well, but I will look on one and frankly, I will cut and solder the wires if needed because I am fairly certain the connector comes off the alternator anyway.

    But you are correct, it is the voltage signal to the ecu. Nations said sometimes in certain situations it can be a part in the alternator.
     
  6. keith89

    keith89 Well-Known Member Established Member

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    Any luck with this? I haven't had a chance to check as my fuel pump is at magnafuel for a refresh.
     

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