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Electrical Gremlins (charging circuit)

T

TimAUS

Just got it firing!
Joined
Oct 1, 2015
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Location
Norway
Hello all,
New to the forum so bare with me.

I have been rebuilding a V50 Mk3 from the ground up into a cafe racer. As part of the work i stripped the electrical system and started from scratch simplifying the multitude of connections and upgrading some components.
The bike is running with no problems however the charging circuit is causing many headaches.

I upgraded the old seperated reg/rec unit with an aftermarket unit, this one to be exact.
http://www.electrosport.com/street-...uzzi-bosch-alternator-regulatorrectifier.html

So the problem i am getting is once the bike is running the voltage continues to climb up pass 15/16V. so what i have done thus far is:

1. Confirmed the AC voltage off each terminal on the bosch alternator is producing a voltage similar to each other and that it increases with engine revs up to 80V AC approx.
2. checked the earth on the stator (the new reg/rec unit runs a dedicated earth back to the battery so no problems there)
3. Ran through the trouble shooting instructions from the manufacturer and concluded with Reg/Rec unit was fried so took it back to the shop and got a warranty replacement. However after wiring in the new unit I'm now experiencing the same problems...

The reg/rec unit comes with a wiring diagram for installation. The only part which is a bit vague is the orange wire which goes to the ignition switch. It appears this system does not use the charge warning light that the old system incorporated. i have wired the ignition switch wire into the main relay which gives power to the bike however i fear that this is incorrect...

I started investigating the voltage across the bike when running and found that the voltage when measured away from the battery was bouncing severely, oscillating from 2-3V up to 18V. The voltage was more stable at the battery but i think the voltage was being dampened out by the large lead acid battery.

Im completely at a loss to what is going on and am hoping someone more electrically inclined can point me in a possible direction for further investigation....
 
The alternator is working correctly. If you wired the unit by the directions, then the new regulator/rectifier is at fault. I've looked at the PDF instruction sheet for the unit. It doesn't show the connections for the Black and the Brown wire. My guess is the Black is the original wire from the bike harness that goes to ground. As to the Brown wire, I have no clue as to where it should go. Looking at the schematic, https://www.guzzitech.com/forums/resources/1977_v35iii_v75.149/download?version=149 I don't see a brown wire in the charging circuit. My guess is the brown is to provide reference voltage, and I don't know where that connection should be. Since you removed the original harness, I don't know where to point you.
 
I cant imagine that another reg/rec unit is faulty straight out of the box...

I will go over the unit tonight with the multimeter and confirm all the diodes are intact. Also check over the rotor and stator to confirm the resistance values are correct and double check the volts coming off the 3 phases is correct.

Might also re-assemble the original reg/rec unit onto a bread board and wire it in for comparison. The only reason is got rid of it was to reduce clutter. Perhaps this decision is costing me.
 
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