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Electrical problem

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by MZ, Jul 10, 2006.

  1. G`day
    I have been having a lot of trouble over the past 6 months with the MZ electrics and thought someone might be able to shed some light on the problem
    What is happening is it will run fine without lights on but as some as you turn them on it will stop ( only when you come to a stop at lights etc will keep running when on the move ) .So far I have had it to 3 bike shops to have the alternator checked and all agree its charging . Next 1 said the battery might be stuffed so I put a new battery in and I run fine for 3/4 weeks with lights on and in cold conditions them all of a sudden it started stopping again when lights are turned on . Next I was tould the voltage regulator might be stuffed (its an old mechanical type like on VW beetles ) so I got another one put it in and now the charge light on the speedo stays on and it still stop when you turn lights on . I have been told to get rid of the old type VR and put a solid state one in but I really don`t want to spend another lot of money if thats not the problem which it might not be .
    I need some help desperatly before I burn the bloody thing :evil:

  2. Sounds to me that your light circuit is competing for current that supplies either your coils or ignition system (if electronic ignition).
    One way to check this: one is to use a multimeter to check voltage at the coils when running, turn headlights on and see what happens. It could also be a suspect ignition switch, but I don't know th wwiring setup for your bike.
    What is a fairly common modification on the older Kawasaki Z's is to run a switched relay to feed the coils only. On the Z's(and most bikes), teh power for the coils takes a long, convoluted path through ignition switch, kill switch, maybe a clutch lever switch and a sidestand switch. All this, with some old, coroded connections, can rob an easy 2 volts. Take off some current with the headlights and you stall.
    The relay mod is easy, and gets you a full 12v at the coils.
    Does the bike idle rough sometimes?

    Regards, Andrew.
  3. Thanks
    I will have a look and see how many volts i get
  4. Sounds like you have some partial short in the lighting circuit.

    It's drawing more current when the light is turned on. Check for cracked or worn wires.
  5. Are any fuses blown?

    I had a problem with my bike - if I indicated right it would cut the bike out (that was a friggin' fun merge the first time that happened!).

    I found it was blowing one of the fuses. We tried a few new fuses and it kept doing it.
    Finally just put a 25amp fuse instead of the std 15 in there and it's been perfect ever since.

    [edit] I'll just make a note that YES we checked all connections and replaced a few contacts to no avail. I don't solve every problem with 'chuck a bigger one in there' - fuses DO do an important job... sometimes :)