Electrical weirdness after gearbox swap, help please!

  1. Frequent Poster Joined: Sep 2010 Bristol Posts: 906 Saxo 1.4i SX 3dr, 106 (engine swap under way), p
    #1
    Right, bit of help required please people, this has me stumped.

    I dropped the engine in my quiksiler in order to swap out the shagged gearbox. Put it all back together and connected it all up no worries. However, when I turned the key to position 2 (i.e. run position) the starter motor started to run (just the motor, not the solenoid although it did try and chatter a little when i did it subsequently). I thought I'd try the start position just to see. Turning the key against the spring results in the motor stopping.

    Turned it all off and disconnected the battery. Battery voltage shows 12.3v when with key off and 11.5v ish when the motor is running. A continuity (diode) check between the battery positive lead and the gearbox earth bolt shows nothing when the key is off, but with the key in positions 1 AND 2 shows a connection between these two points. What the f*ck is going on? The only thing I can think is maybe I shorted the starter/solenoid by spraying a load of wd-40 into the gear end (it would stick when starting a fair bit). I don't think it would present these sort of symptoms though?

    Ideas/advice anyone?
  2. Saxperience Forum Bum Joined: Apr 2013 Jarrow Posts: 4022 2003 Icelandic Grey 16v VTR 1991 Daihatsu GTti
    #2
    Is the solenoid is clicking if say there's not enough juice to actually spin the motor. If recheck your earths and make sure you've not pinched a wire.
  3. Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.
    #3
    Are all the earths connected up properly & the connections too the starter are they on the right way?
  4. Frequent Poster Joined: Sep 2010 Bristol Posts: 906 Saxo 1.4i SX 3dr, 106 (engine swap under way), p
    #4
    Right, I've changed the starter for another one, just to rule out a shorted solenoid. New one is presenting the same issues. Key in position 2 = starter spinning but no solenoid. Key to position 3 = motor stops.

    Can't see anywhere where I've pinched wires. Connections to the starter solenoid are:

    1. a small wire with a ring terminal to the small stud with the 8mm nut,
    2. to the top large stud, a wire from the loom with a large ring terminal (I assume this is the one from the alternator?), and a wire direct from the +ve battery terminal.
    3. bottom large stud connects into the motor itself via a braided cable.

    What the hell is going on?
  5. Established Member Joined: Jan 2008 Scotland Posts: 1764 Because racecar
    #5
    I think You have a positive running where it shouldn't be. Check the positive running to the fusebox in the enginebay is done correctly and check the negative terminal on the battery is wired properly.
  6. Frequent Poster Joined: Sep 2010 Bristol Posts: 906 Saxo 1.4i SX 3dr, 106 (engine swap under way), p
    #6
    Yeah something's up with it, but I can't work out how I could have screwed it up. The +ve has 3 connections from the terminal and the -ve has 2. :-(
  7. Established Member Joined: Jan 2008 Scotland Posts: 1764 Because racecar
    #7
    Any chance of some picturss of the wiring? So at the starter, geaebox earth, fusebox power and the plugs for the engine loom into the car
  8. Frequent Poster Joined: Sep 2010 Bristol Posts: 906 Saxo 1.4i SX 3dr, 106 (engine swap under way), p
    #8
    Right, had a bit more of a play with this today. Turns out I'm a grade A pillock. The motor noise on key position 2 turned out to be coming from the power steering pump!

    I might have an issue anyway though, as the car showed absolutely no signs of even trying to start after I'd unplugged the ps pump. I tried jump starting it after leaving it hooked up to the other car (idling) for 15 min or so. I even tried tow starting it and it wasn't having it. I have bought the battery in to charge it but it was showing around 12.2v at rest (before I tried jumping it) so it was a little low but it should have at least tried surely?

    chompy, starter connections are as per my post further up. -ve connection runs from the terminal direct to the gearbox stud on the bell housing. The other lead from the -ve terminal attaches to the body right by the battery tray.
  9. Frequent Poster Joined: Sep 2010 Bristol Posts: 906 Saxo 1.4i SX 3dr, 106 (engine swap under way), p
    #9
    Ok, definately something else going on with this. I tried the fully charged battery in the car this morning and it wasn't having it. Position 3 on the key results in the single green relay in the front fuse box going "click" but no crank attempt from the starter (no noises from the solenoid either). Any ideas guys?
  10. Frequent Poster Joined: Sep 2010 Bristol Posts: 906 Saxo 1.4i SX 3dr, 106 (engine swap under way), p
    #10
    Righty, checked the wiring resistances to make sure the earths are OK. Wiring between body and -ve battery terminal, and gbox to terminal shows jack all resistance, so I would say that's fine. I then checked the voltage presented on the small solenoid terminal when the key was moved into position 3, result was zero!

    So, it looks like I have an issue between this terminal and the ignition switch. According to my Haynes manual, the only other component in that line is a fuse in the "battery fusebox" which I'm guessing is the small high amp box near the brake servo? Anybody have a diagram of fuse does what in this box?