1991 Electrical gremlins.

Discussion in '3rd & 4th Generation 1990-1997' started by HamHock, Mar 11, 2019.

  1. HamHock

    HamHock New Member

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    1991 rc36/1 keeps having electrical hiccups. Thought I had this nailed, I thought wrong.

    Here is a rundown of what happened and what I've done.

    Last fall the R/R went out and melted the starter relay and took out the battery too.

    Replaced with OE style relay, Caltric battery and a Chinese 5 wire R1 R/R.

    I replaced the three yellow wires going from the stator to the R/R with 12G wire.

    The R/R was re-wired with the positive going directly to the battery with a 30A fuse.

    R/R is grounded to the frame at the same spot the battery is grounded.

    My problem is that the 30A fuse in the starter relay keeps melting. The plastic shell is getting hot enough to melt without blowing the fuse. This has led to the bike sporadically dying in traffic, and loosing all lighting in the process. Am I just going to have to relocate the relay to a cool spot? Ducting?
     
  2. RllwJoe

    RllwJoe Insider

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    If you have a muti-meter let us know what your output is at idle and 5000 RPM +. Have you done "the drill"? I would be afraid, very afraid of the "Chinese" R/R!
     
  3. HamHock

    HamHock New Member

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    I checked it after install and had a temporary volt meter mounted on the dash for a while and was getting a consistent reading between 14.2 at idle and 14.9 above idle with no low voltage situations and no peaks past 14,9.

    I will take new readings when I get a chance this week. Parts are finally here for my permanent volt meter install on the fairing so from here on I'll have a live reading at all times.
     
  4. skimad4x4

    skimad4x4 "Official" VFRWorld Greeter

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    14.9 sounds awfully high except perhaps for a very brief period straight after the bike has been started up when energy drawn from the battery starting the bike needs to be replenished quickly. 13->14.5 is about what a healthy RR should be putting out - however it is worth saying ultra cheap aftermarket voltmeters are not known for their precision, so it all depends on what quality test equipment you are using.

    What really worries me is your mention of the starter relay fuse which should not really have a hard time. Ok it carries a lot of current but that is only for brief periods, and the fuse should be ample for normal operation. Indeed that relay should only activate (and be carrying any significant load) very briefly - just whilst you hold the starter button down. Once the engine is running there should be no power at all flowing from the starter switch to the relay and certainly no heavy current flow being sent to the starter.

    Are you saying that relay is getting hot whilst riding not just when the engine is being started up? If so that suggests you may have a starter switch wiring fault, or a faulty relay or possibly the starter is on its way out. That relay should definitely not be getting hot enough to blow the fuse whilst riding. I would certainly see if there is any + volts detected on the starter switch side of the relay "after" the starter switch has been released. If there is then you may need to clean or replace the starter switch.

    SkiMad
     
  5. Diving Pete

    Diving Pete Member

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    Check your starter relay is working correctly & hasnt in the past been rewired..
     
  6. HamHock

    HamHock New Member

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    Sorry for taking so long to get back to this. Between rain and work I hadn't had a chance to even look at the bike.

    The battery wasn't holding a charge so I replaced it and hardwired in a permanent voltmeter. After installing the battery I tried to start the bike but the start button did not do anything. I did hear a clicking noise when pressing the button. The sound came from around the gauge cluster.

    I ended up jumping the starter relay and the bike fired up no problem. With the bike running at idle in is charging at 14.0V. When revving the engine to around 5k it is still reading 14.0

    The starter relay was replaced by me about 2 months ago. and yes, I am saying that where the main, 30A fuse is located is getting hot while riding. I can not tell if the relay itself is getting hot or if it is just the fuse leads. Either way the result is the fuse is getting hot, hot enough that the plastic around it is melting and the fuse is losing contact. The fuse is NOT blowing out in the traditional sense. It will still have continuity after melting.

    I have multiple DVOM's, all of them cheap but when I take readings with them I get the same results. Yes I know they are not precision instruments but I also know we're just playing with low volt DC here. I appreciate the replies and I hope you guys can help me get all problems sorted.
     
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