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electrical system faults

Discussion in 'Bling and Appearance' at netrider.net.au started by smiley235, May 26, 2007.

  1. Hi, my fuel light always remains on even when its full, its been like this since I got it so I'm assuming a short somewhere perhaps. Also, sometimes a red light comes on next to it and i'm not even sure what the red light means. Just wandering if this is a common problem, and if it isn't, if anyone has a wiring diagram so I can trace the problem,


  2. Sorry google, I forgot to mention its a suzuki across. :p
  3. I know this question is a bit tricky, so i'm just gonna bump it this once. :?
  4. have u checked the wiring leading into the fuel tank.
    could just have been disconeted during the last service
  5. hmm, i'll check that out then. Just wasn't sure how the fuel light was triggered.
  6. Do you have the owner's manual? If so what does it say what this red light is for?

    As for the fuel light, it's probably a stuck float switch in the tank. How easy is it to remove the tank and give it a bit of a shake? Or even to just tip it upside down?

    If you have a wiring diagram and can find the two wires (presuming that there are two wires) to the switch, if you can put a meter across them to see if the switch is closed. If it is, then it's the switch. If it isn't then it's probably a wiring fault. Unlikely, but possible.
  7. I dont have the owners manual. Not sure how to remove the fuel tank either. But i'll test the switch if I can locate the wires.
  8. i would suggest stuck fuel level sensor.
    it might be a bit hard, but lift the bike above your head and shake it :p

    get the manual, plenty of places to buy it or download it for *cough* evaluation purposes (use google) and read up ;)
  9. hmm, I might just do that, thnx
  10. ughh comon people u donnt need a manul to take of ur dam fuel tank off u need a 12mil spanner and thats it.

    its not rocket science
  11. This is an Across. I understand that the "tank" is a glove box. The tank is actually under the seat somewhere.

    Anyway, if he wants to fault find he'll need a manual with a wiring diagram so he can locate the correct circuit to test.
  12. :eek:wned:

    pays to know yer shit eh? :LOL:
  13. got myself the manual, their lurking all over the net. Now the wiring diagram is shrunk down alot in the pdf file so when you zoom in to see something closer, the resolution makes it all distorted and hard to read (ie there are a lot of loops represented by dots but the dots arnt appearing very well), so i'm gonna try and draw out the circuit just for the lamps and then post it up. So far, i've realised the red light means the reserve tank is low too.
  14. Ok, i've drawn out what I can see. The stuff in red means it couldn't be made out so I just assumed. Before I start fault finding, does any1 think there is anything wrong with it so far. After the diodes, it seems to go to the oil pressure switch and a terminal in the speedo but i'm not sure why as that would mean they would only get power if one of the flow switches was closed.

  15. If it was my bike I would be more keen to find out what the mystery red light is indicatiing...!
  16. If I'm reading that circuit right the bottom sensor or switch goes to the Resever Tank light and the other one to the half tank light.

    Am I correct in assuming that with half a tank, one light illuminates, and when on "reserve" the other light comes on?

    Interesting to know what that wire from the common of the two diodes goes to.

    Now, you just need to disconnect the wires from the two sensors and check them for continuity, etc.
  17. yeh, thats pretty much what I assumed, red light comes on for reserve. The circuit path after the diodes has me stumped though, too busy at work today to test it all though. And thanks for the last tip about disconnecting the sensors, it would be a good starting point.
  18. Suzuki Across fuel light

    I'm not sure, but looking at the shitty wiring diagram in the manual, can I suggest you have it back-to front. b/w on the fuel sensors go to the -ve terminal of the battery (not +12V). This makes sense since fuel is flammable - you don't want a short between the tank (ground, 0V) and the 12v line should something fail. So all switches and the tank are at 0V (or ground rail)

    Then, the common of the two lamps is on a fused +12v line (O/G) which has a fuse back at the fuse box.

    If that is correct, then the two diodes at their common point (marked G/Y) run back to ground with what looks like a resistor in the connector.

    so, the fuel sensors act as bypass circuits to the resistor, allowing enough current to flow through the shortest circuit with the least resistance and light the fuel indicator. When the fuel sensor isn't activated, the current path is through the resistor which limits the current to the point where the light filament doesn't glow enough to be seen. The resistor is probably there so that some current is always passing through the circuit to prevent small arcs when the fuel sensor makes/breaks contact depending on fuel volume?

    Does anyone agree?
    If this is the case, assuming shaking the tank doesn't work and the sensors are not stuck/lodged, then it may be a wiring/switch fault with the respective sensor.
  19. wiring.

    so the two diodes keep the two ground (0V) circuits separated such that the switches and lamps work independently. I think it is quite a smart design.