89 nc30 charging problems/melted wires

[davedrave]

hi,

New to the site, been using the forum to diagnose my charging problem but theres a couple variables that have popped up making it hard to know where to go from here, plus im a complete novice with electronics so please forgive my ignorance

Il start with the biggie to save people reading the whole thread in case the most recent thing fixes everything. Just now I spotted these charred wires on the right side of the bike resting on what I think is the clutch cover





three yellow wires, pretty badly charred and there is some soot on the cover where it was in contact with the case, I dont know if the heat of the engine melted the wires or if they melted themselves. They did seem to still be fully intact before i inspected them further when one of the three wires fell apart in my hands.

So what are these wires? Can I trim them back and twist them back together like they were or should i solder/crimp them? Would this be causing my charge problem?

Heres the full story if the above isnt actually the cause, because the bike still switches on with those wires in that condition

So bought the bike recently, getting home the tach dropped dead as did the indies but the headlight still worked, (turned out to be a bulb causing a short but id read that it was a sign of charging failure) by coincedence, got home and although the headlight was still bright there wasnt enough juice to start the bike.

Ive a crashed bros 400 with a working reg/rec so I threw that in with the help of a couple threads on this site, I soldered the rec to the existing wires and joined it up using the same crimp connectors the old rec used. On the phone to the previous owner I told him what readings I was getting with a multimeter and he said it sounded like id fixed it. So replaced reg/rec and charged battery and I had no problems until about 3 weeks later when the battery again couldnt start the bike, I dont know if the battery charge kept it going for 3 weeks slowly draining or if the melted wires caused a new problem, but for the last week been going around with a battery charger and screw driver at all times (its like having an electric powered bike having to charge it every night )

Since that, Ive put in the battery from the bros, which was newer than the existing battery in the vfr, however had gone a while without a charge. regardless heres my findings since AFTER the rec change.readings taken from the battery terminals

VFR battery (cbtx9-bs not the right one afaik)
Off:12v79
off with Lights On: 11v85
Idle:13v4
Idle with lights on:12v
5k revs:13v5
5k revs with lights on:12v5

BROS Battery
Off:12v96
off with Lights On: 12v15
Idle:13v8
Idle with lights on:12v27
5k revs:13v5
5k revs with lights on:12v6

To me there isnt much difference in readings but someone else might be able to tell me im in the clear? I never had charging problems with the bros so Im inclined to eliminate both the battery and the rec but perhaps the battery has been weakened from being dormant for a while

[davedrave]

wow a discusion of 41 replies in one forum and not one reply in this, is this an american forum with everyone asleep because that would explain it?

[porndoguk]

jeez man, your an impaintent one, this is an uk based, but has an international member base,

your melted wires are NORMAL unfortunatly, mine did it, it seems that the connectors at the plug become loose over the years and then the heat starts to generate from the high resistance caused.

so aslong as the 3 yellow phase cables (producing 50VC AC) are insulated from the bike and each other wire youll be ok, but will need to crimp and solder new spades onto the ends and ensure and good firm connection.

charging system there are LOADS of guides on here that are talked about on a daily basis, because its what VFRs are famous for going wrong with,

12V with headlights on at idle seems a little low, so maybe the alternator is on its way and the stator coils are over heating and causing the increase in current and load deamand on the 3 yellow cables.

you need to test all the charging outputs with multimeter set to ohms. there procedure is also in the haynes.

Rick

[davedrave]

cheers sorry for the impatience was hoping to get a crack at it before dark

[porndoguk]

cheers sorry for the impatience was hoping to get a crack at it before dark

yeah no problem, hope the above helps.

[davedrave]

tested between the yellow wires and they read 40v but i only crimped i didnt solder, il do that tomoro and check

[davedrave]

Didnt make much difference, il have to get at that alternator soon. Is it safe to bypass the loom to the reg/rec with fresh wire?

[banoffee]

mine had this problem. replaced alternator in the end after just trying the battery and reg/rec

[amorti]

Didnt make much difference, il have to get at that alternator soon. Is it safe to bypass the loom to the reg/rec with fresh wire?

Yes in fact it is a pretty good idea given the state of that bit of your loom. You could solder three wires on starting from before the break, run them as a separate loom to the regulator and use Fbl6 from vehiclewiringproducts to plug into the original wiring loom. Be sure to use thick enough wire!

[chrisja2]

I have exactly the same thing on mine.