Help regarding blown fuse 'B' and no Fuel Pump

Discussion in 'Mechanics Garage' started by keeena, Sep 4, 2007.

  1. keeena

    keeena New Member

    Joined:
    Jul 9, 2007
    Messages:
    123
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    MA
    I'm looking for some suggestions in case theres anything common to the VFR that may be worth looking at. My bike died the other day while cruising in gear ('02 ABS). Was unable to restart via starter or via bump-starting while coasting down the hill I was on. Bike has PCIII & O2 bypass (the Dynojet plugins).

    This is what I've got so far while I was at the side of the road:

    - Fuse B may be blown. It was seriously melted, but may actually still be carrying a current (need to test it). The short R/W wire (between fuse and the in-line plug) has melted some of the insulation and the metal connection inside the plug seems to be fused together due to high current(?). This short bit of wire doesn't seem to have chaffed on anything though...no obvious shorting/grounding. R/W wire after the plug seems to be perfectly intact, no melting or anything.

    - Fuel pump doesn't turn on when flipping engine cuttoff switch to "ON (Run)". If I pull Fuse B, and then re-insert: the first attempt will cause the Fuel Pump to click once very briefly, but no "whhirrrr" noise (not priming). Subsequent attempts won't even cause pump to click. Pulling and reinserting fuse B will cause the click again (but only on first attempt after pull/reinsert).

    - All other fuses completely intact (Fuse-A and small fuses under RH dash panel). Gauges, lights, starter motor, etc...all OK.

    -PCIII does not light up and do its normal POST. I disconnected it from the loop, but doesn't seem to make anything better.


    I have not had a chance to look at the bike since trailering it home. I'm looking at the schematic now, and the R/W wire (Fuse B) only provides power to the engine cutoff relay.

    Does the engine cutoff relay kill the F/P? And would it also cause PCIII to not power up? If so, I'm guessing/hoping the R/W wire (Fuse-B line) may have just shorted somewhere OR engine kill relay may be toast. Is that common on the VFR?

    I know that TOS, Kickstand and other idiot-proof switches can prevent starting the bike. I wouldn't think that any of those are the issue, but know I may have to look at them if I can find an obvious issue w/ the wire.

    Any other thoughts appreciated.
     
  2. keeena

    keeena New Member

    Joined:
    Jul 9, 2007
    Messages:
    123
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    MA
    I finally looked at this tonight for a bit and I'm still stuck...thoughts?

    The Fuse-B line runs directly to the Engine Stop Relay (wire is White/Red at battery but changes to Black/Pink stripe @ relay).

    1. Key in Off position: Bl/Pi = 12.8v
    2. Key in On, cutoff switch in "kill" position: Bl/Pi = ~6v
    3. Key in On, cutoff switch in "run" position: Bl/Pi = 2.75v

    Can anyone confirm what the voltage *should* be on the Black/Pink wire at the Engine Stop Relay? I was surprised that the voltage dropped like this...I expected it to stay around 12v. ??

    Again, bike will crank perfectly fine. The 2 things I notice right now are that the Fuel Pump doesn't turn on and that the PCIII does not start up (perform POST). I don't think FP is shot. The FP Relay is only providing the 2.75v on the brown wire (from the Black/White lead). So I think the root issue is this power drop...something may be abnormally grounding? I'm kind of concerned that it may be the ECU.

    Some other stuff I tested:
    Pulled and tested Fuel Cut and Engine Stop Relays: OK. Bank Angle Sensor OK. Battery is good, tried another known good battery w/ same results. All fuses intact. I put the bike into dealer mode and I don't get any blinks of the FI light.

    The only other connection that Fused-B line (Red w/ white stripe) makes is with the R/R. I'm not sure if a faulty R/R could create this particular problem.

    If anyone could help me make some headway, I'd def. appreciate it.
     
  3. Bubba Zanetti

    Bubba Zanetti Member

    Country:
    United States
    Joined:
    Jan 27, 2007
    Messages:
    3,383
    Likes Received:
    3
    Trophy Points:
    53
    Location:
    Delaware
    Map
    Keeena:

    Oddley a bad RR could cause your particular issue. When I had RR problems I went through a ton of posts here and other VFR forums and "blown fuses" did show up as a symptom.

    I would test your voltage output with a multimeter. With the bike warmed up, rev the engine to 3-5000 rpm and hold it and see how many volts your multimeter reads.

    BZ
     
  4. keeena

    keeena New Member

    Joined:
    Jul 9, 2007
    Messages:
    123
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    MA
    Can't test power output because the bike won't start - Fuel Pump doesn't turn on, PCIII does not light up.

    I do not have any blown fuses, Fuse-B plastic was seriously deformed from heat(?), but still carried a current (replace it anyways for the moment). R/R wires and Stator wires all appear in good condition, no fraying/shorts/burns/etc... that I can see.
     
  5. Bubba Zanetti

    Bubba Zanetti Member

    Country:
    United States
    Joined:
    Jan 27, 2007
    Messages:
    3,383
    Likes Received:
    3
    Trophy Points:
    53
    Location:
    Delaware
    Map
    Can you test the battery?
     
  6. Bubba Zanetti

    Bubba Zanetti Member

    Country:
    United States
    Joined:
    Jan 27, 2007
    Messages:
    3,383
    Likes Received:
    3
    Trophy Points:
    53
    Location:
    Delaware
    Map
    Burnt wires do not always happen either, so what happens when you turn the ignition on? Lights come on? Anything?
     
  7. keeena

    keeena New Member

    Joined:
    Jul 9, 2007
    Messages:
    123
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    MA
    I get all gauges, all lights. Everything seems perfect other than Fuel Pump doesn't prime and PCIII doesn't light up. Starter turns motor over perfectly fine. Battery has solid 12.7-8v, but I don't have a way to test amperage/CCA (if thats what you're asking). But I did try w/ another known-good battery from another bike...doesn't help the situation.
     
  8. Bubba Zanetti

    Bubba Zanetti Member

    Country:
    United States
    Joined:
    Jan 27, 2007
    Messages:
    3,383
    Likes Received:
    3
    Trophy Points:
    53
    Location:
    Delaware
    Map
    Hmmm...well if you burnt the fuse up I would begin checking all your electrical connections from your starter button to and from the fuse, etc. Maybe something else is burnt too.

    BZ
     
  9. keeena

    keeena New Member

    Joined:
    Jul 9, 2007
    Messages:
    123
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    MA
    I'm thinkin the semi-melted fuse may not be related. I think it may have melted due to proximity to heat or a prior short in the wire immediately following the fuse (which has since been fixed). But who knows. I think this point i'm dealing with a shitty connection or ground on a loop somewhere. :frusty:
     
  10. Bubba Zanetti

    Bubba Zanetti Member

    Country:
    United States
    Joined:
    Jan 27, 2007
    Messages:
    3,383
    Likes Received:
    3
    Trophy Points:
    53
    Location:
    Delaware
    Map
    I have the same feeling too. However, your RR may have been the main cause.

    Keep me posted on your findings.

    BZ
     
  11. keeena

    keeena New Member

    Joined:
    Jul 9, 2007
    Messages:
    123
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    MA
    Will the bike run w/o the R/R plugged in?
     
  12. Rangerscott

    Rangerscott New Member

    Joined:
    May 9, 2007
    Messages:
    426
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Texas
  13. keeena

    keeena New Member

    Joined:
    Jul 9, 2007
    Messages:
    123
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    MA
    Thanks for the links RangerScott.

    Well, I've got her running again. All I ended up doing is completely bypassing the the Fuse-B line and the little plug about 3" downstream of the fuse. It originally tested OK for continuity & voltage, but I guess the wire or plug wasn't able to handle more than test current. The plug was corroded and fused (similar to what others reported). I bypassed this w/ a test line and bike started right up 1st try.

    I'm not 100% clear what causes Fuse-B to melt/short. From what I can gather, its a good idea to replace/bypass a couple of the ground connections (green wire in the blue plug on LHS and green wire in ECU plug). Is this it? Or is there anything else worth doing as well? Sorry if I've missed all the answers in those linked threads...its hard piecing the bits of info together.

    I did check all of the harness plugs, they all seem intact w/ no signs of melting or fusing.

    One last thing - I left the bike w/ the ignition and kill switch in the ON positions for ~30 mins while on the computer. This brought the battery down to the point that it could not start the bike; barely even turns over. Keep in mind that the headlights are NOT connected. This is a brand new battery and I don't think it should have drained this quickly. So I do think it goes to show that something is pulling excessive current somewhere.

    PO did have had the alternator replaced due to the recall.
     
    Last edited: Sep 9, 2007
Related Topics

Share This Page