Electrical Mystery

[Urban_Legend]

Hi guys.
After our recent Aussie FJ rally I was making my way home and decided to make a little detour to a lookout I had often ridden past but never gone into. Unknown to me it turned out to be 15km of dirt road. About 10km into it I noticed my volts drop dramatically. I turned my headlight off to conserve the battery and continued another 150km home.
I had a similar issue once before with a bad connection with the brown voltage reading wire for the regulator. So when I got home i pulled the fairing when through the harness and found that the diode thingy from the upper end of the harness had gone missing.

Easy fix, so sourced another one form a friend in Sydney , plugged it in and no charging.

Plan B. Sick of the wiring issues with this bike and sure it was a bad connection,  I borrowed a complete harness from another friend plugged it all in. Same thing. No charge from the alternator.

Trying to get another alternator now (I have tried bypassing the regulator with the reg mod no difference) and I an hoping this will work.

Any other suggestions?

[Sparky84]

Any other suggestions?

No disrespect Mark
But,
Stop doing anymore "electrical" wiring,  


please..


BTW, what was the diode thingy doing in the fairing?

[Urban_Legend]

That's where it lives Allan.
On the right side near the air duct.

[roverfj1200]

Mark before doing any electrical work you need a good multi-meter and you need to know how to use it and what readings you should get. So first question is ......... have you??

[oldktmdude]

   Mark, that diode thingy has nothing to do with the charging circuit. It links to the neutral switch, clutch switch and on US models, the side stand switch.
It works in conjunction with the relay/blinker unit and stops the bike starting in gear without the clutch pulled and cuts the engine if the side stand in down and the clutch released.
   Alf's brother had an alternator problem on his way home from the Rally. We changed the voltage regulator (Bosch RE55) at Bathurst which made no difference. When he got home, he had the alternator checked out by an auto electrician and the problem turned out to be a detached wire inside the alternator. Not one that had been altered during the external reg mod but an original factory installed wire. You going down a dirt road (possibly rough?) may have had a similar problem. My advice is to get it checked out by somebody who knows what they're doing, Good luck.
   Regards, Pete.

[Urban_Legend]

Yes, I have a multi meter and a test light. Multi is reading 12.3volts at the alternator.

[roverfj1200]

Yes, I have a multi meter and a test light. Multi is reading 12.3volts at the alternator.

That is just batt voltage Mark.

You will need to test

Winding Ohms and continuity.
Secondary Ohms and continuity.
Resistance of brushes and state.
To do the FE55 mod you must remove the ordinal reg and solder a solid bridge in to bypass it.
If you tackle electrical issues with a replace and try mentality you are wasting time and money.

[Urban_Legend]

Just going on a process of elimination Richard. Going from what I had go wrong last time.
I now know it is not the wiring harness  which brings me down to the alt or reg. I was thinking that I had replaced the reg last time, so less likely to be that, but not impossible.