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Testing reg/rec!!

Discussion in 'Technical and Troubleshooting Torque' started by rodgonzbea, Apr 8, 2010.

  1. Hello, i will once again ask for help to try to work something out on my pride and joy..
    To make the story short..sort of.. bought the bike, soon after had problems with the battery, got a new one, and killed it.. many times, in fact. Got a reg/rect fro the wreckers and put it on.. battery still died. But last week my neighbour comes in with his multimeter, and tells me the bike its not throwing back enough charge to the batt. We look at the reg/rect, and one of the cables (black) is super hot. I had joined the wires manually as the reg rect was slightly different, but according to the dude at the wreckErs it was still ok. So the black wire had almost burned the duct tape off it. When you turn the bike on it got really, really hot. Only the black.

    A mate of mine said, why don't you bypass it straight to the battery? So I ran a wire from the reg/rect to the battery. Battery still dies. I find the wiring diagram, says black goes to ground ie chassis, not -ve on battery. So i wire that to the chassis. I got me a multimeter. With the bike running, battery starts at 12v and slowly starts going down..turn the lights on and it drops to 10v, and quickly down.. But, if i leave the red testing needle on the battery+, and the black on the wire to the chassis (the one i bypassed straight from the reg/rect) (bypassing the coupling, that is, and the wiring harness), IT STAYS AT 12??

    Do i then need to run that cable back to the battery? the reg rect gets warm, so something is going through it, but not hot. I also reckon there is a very high chance that the battery is now kaput, as it has now being run dry about a dozen times, plus while charging it my lttle ones have also knocked iton its side a couple of times.. but I don't want to buy another battery if the problem is still with the reg rect... HELP!!!
  2. You are playing with a lot of energy and have incorrectly wired up the reg/rec already. Just guessing is going to get you (and your bike) into more strife. Might be time for the auto elec to step in or at least someone (there appear to be many on this forum) with appropriate experience.

    If you want to have a go yourself you can find technical help at http://www.electrosport.com/technical-resources/diagnosis-center.php
  3. Might be an idea to have some paragraphs above as it's a hard read in that format.

    Firstly it shouldn't matter whether you wire it to the battery or the chassis, provided the chassis is well earthed to the battery. Check this.

    Secondly, what do you mean you run the battery "dry"? Flat or dry?

    If you run it dry, then it is phucked and that could be causing the regulator to overhead and could stuff the regulator. It may have even done it.

    What type of bike?

    chances are you need a new reg. Someone here pulled one apart the other week and replaced some internal components, but is seems to me you are not electronically inclined.
  4. Thank you ibast.. i am not very electronically savvy.. not enough to pull the part in pieces, i can usually work something out if i understand how it works...usually..

    Its a yamaha SRX 250 1985..

    I meant run the battery flat.. meanwhile ill go and have a look at the battery harness.. thanx for responding!!
  5. I can imagine regulators off any number of bikes fit those things. 80's Yamaha trail bikes come to mine
  6. Stop listening to your mates!

    Use the service manual, or get one if you don't have it - there will be a section on diagnosing charging issues. Work systematically through, testing stator/alternator (usually measuring resistance between the three output wires) then the reg/rec (output) and then the battery and how the voltage reacts standing, running, revving. I can give you the equivalent for a GSXR, but not sure what the parts comparison would be like.

    Work through it and you'll find the problem. It sounds like a dodgy reg/rec, but that could have happened because of a problem with the stator. Ditto for the battery.

    Final note - the more you fark around with cutting, re-routing and splicing wires the greater the chances for a dodgy connection, so I'd minimise that if you can.
  7. Id be more looking at a burnt out stator/generator than a dodge reg/rec.

    Take ya stator/genarator cover off and check that its not burnt out.
  8. That's definitely a possibility - if you test the stator output leads and get no continuity (resistance off the charts) then it's probably fried. It'll look like this:
  9. Assuming that the black wire is the earth, I'd have a guess that you've got a poor earth connection somewhere. Or multiple places. It would be getting hot 'cause there's a fair bit of resistance somewhere along the way. Also, make sure you solder and insulated all the joints after you are CERTAIN they are correctly wired. Those crimp fittings are shit for charging circuits. Even quite a few auto leckys don't seem to understand this when wiring in aftermarket rec/regs.