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Wiring my 1978 xs400

Discussion in 'The Garage' started by Wil Mueller, Sep 8, 2019.

  1. Wil Mueller

    Wil Mueller XS400 Member

    Hey guys i recently rebuilt my carb and got all the bits for a cafe racer build i just need to do the wiring and im kind of confused on where the condenser and regulator rectifier go in the wiring. Im doing kickstart only with a 12V 1.3Ah battery does anyone have a wiring diagram that could help with this? Most wiring diagrams i find dont even show the condenser.
  2. BBS360

    BBS360 XS400 Guru Top Contributor

    Two different examples attached. Both show reg, rec, and condenser.
    Both leave out the negative wire from the rectifier but it can go to ground or a common ground wire.

    Attached Files:

  3. Wil Mueller

    Wil Mueller XS400 Member

    Thanks! What does it mean by points though? I bought mine in pieces and I've been rebuilding it and im not sure if i have points.
  4. Gra900

    Gra900 XS400 Addict

    365F2592-EF4B-456A-A16D-48D6593A2B3E.jpeg Check this photo, the red circle
    If it looks like this when you remove the small cover you have points
  5. Wil Mueller

    Wil Mueller XS400 Member

    So i have 8 wires coming from my alternator, 2 yellow, 3 white, one green, one blue, and one black. The three white go to the rectifier, green goes to the regulator, but im unsure of the two yellow wires, should both be capped or is one of them needed and the other is capped. Also the blue and black wire im not sure, i believe the black might go to the regulator with the black and red wire but im not certain. Thanks for the help.

    Attached Files:

  6. Wil Mueller

    Wil Mueller XS400 Member

    I checked it and i do have points, thanks!
  7. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    If you drop the E-start, all you really need to do is remove the solenoid and just run the red wire to the battery. This is the red wire that splices off the heavier short wire that connects the battery and the solenoid. You can remove the starter and free up some weight too.

    BTW, I use a 4 cell AntiGravity battery and it will turn the E-start no problem. I use the kicker only anyways but its there for emergencies. I figure I can get about 15-20 seconds before the battery is completely drained.

    just saying, it is possible to run a E-start and keep things cleaned up. 120CCA is as small a battery I would go anyways.
  8. Wil Mueller

    Wil Mueller XS400 Member

    Mine doesnt have a solenoid or wiring to it i bought it as a frame, an engine, and a bucket of parts
  9. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    The thicker red wire that comes off the main wire harness, it may have a fabric shield on it and a bullet connector end, this is the main power wire that connects to the battery. If you dont have a harness, Id say its easiest to get a used harness and modify that to your liking. The factory harness has a lot of extra length wiring that can be clipped off. The original fuse box isnt so great.


    I used that shop when I did my wiring. They have the proper plastic connectors and metal fittings, great resource for DIY wiring. They stock awesome fuse boxes, I used the Metri-Pack 280 4 circuit box on my bike. They stock the tools too. I cant tell you how many times Ive used the terminal extraction tools on my bikes and cars, and as a tool for adjusting the idle mix screws while on the road!

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