87' 1VJ parastitic draw

[j0epere]

Greetings from a new Tenere owner!

Finally my long waited 1VJ arrived after 2 months of searching and waiting for it to arrive in Estonia. Now I luckily got my hands full for the winter with various mechanical and cosmetical jobs :)

The previous owner told me that the regulator/Rectifier was faulty, and it was well confirmed by the diode/continuity test + by the fact that the voltage didn't increase withi increasing the RPM's.
He also included a new regulator with the bike and the diode/continuity test showed that the unit was all good. Once installed on the bike the it seemed to be charging the bike as well.

Yesterday after cleaning the carbs i decided to check the voltage on the battery and it seemed that it had run dry over the course of few days. I charged the battery and checked the current between the negative terminal and the wire supposed to go on there. It read about 0.19-0.36 AMPS, the reading didn't change at all when switching the ignition on/off with the key. Didn't have too much time at that point to go over all electrical connections, but i noticed that the current went to "0" when i disconnected either the main fuse(Red wire coming from the starter switch assy) or disconnecting the regulator/rectifier. Not sure if relevant information, but i still heard the "click" coming from one of the relays when switching the ignition "On".

Has anyone encountered a similiar issue before? Seems to me that either the Regulator/Rectfier or the steering lock switch is busted. Not too familiar with the electrics of the bike yet, but 0.19-0-36 AMPS seems like an awful lot of current going through when the ignition is switched off.

Thanks for the help and a picture of the bike as a bonus!

[motorang]

Hi to Estonia
The draw not normal.
From the electrics scheme there are three paths from the battery:
- regulator to alternator (6)
- via fuse to the ignition switch (27)
- via starter relais to starter motor (14). I would suspect the starter relais first (try disconnecting the plus wire coming from the battery to the relais)

It is strange that the parasitic draw goes away when EITHER regulator OR fuse is disconnected, that would hint there are 2 independent problems.

Some regulators have an extra port for a sense wire, which has a draw by definition.
What regulator do you have in there now, and how is it wired to the bike?

Andy

[j0epere]

Hi Again,

ve an extra port for a sense wire, which has a draw by definition.
What regulator do you have in there now, and how is it wired to the bike?

Currently I have a Reg/Rec with the markings "47X-A1 SH569-12". By the looks of it, it seems like the standard unit with 3 phases from the alternator going in and one coming out to the battery. The metallic body of the regulator serving as a ground when bolted to the frame, also one extra ground wire is attached to the Reg/Rec bolt. Detaching this made no difference to the current draw.

I decided to do another test on the "new" regulator and looks like i have missed something. I did the Diode check between the ground(body of the Reg) and the 3 phases going in and 1 phase going to the battery, following that video https://www.youtube.com/watch?v=qg3rcPamp7w. The first half of the video (testing between the 4 pins) seems to be indicating that everything is working OK.

The reversed biase test results:
Multimeters "+" on the ground and "-" on the 3 Alternator phases - I get similiar readings of 0.500 Volts.
Multimeters "+" on the ground and "-" on the phase going to the battery - I get a reading of 0.850 Volts, I'm not sure if i should get any readings on that one.
Reversing the "+" and "-" of the multimeter and redoing the test i get no readings, which seems to indicate that no power is "leaking" through the Regulator, correct me if I'm wrong?

Do my readings indicate to another faulty regulator or I'm i looking in the wrong direction and everything should be OK with the unit

Thanks!

[j0epere]

Did another small check in the garage and now I'm fairly confident that I have 2 differently faulty, but equally useless regulator/rectifiers.

I attached the old(not charging) unit to the bike and the current draw went away.

Also did another test with the new(leaking) regulator:
Attached the regulator to the wiring loom, but didn't ground it to the frame. Also attached the positive wire to the battery and left the ground wire unattached. When measuring between the Metallic case of the regulator(that should be grounded to the frame) and the negative wire that was unattached to the battery I measured 12.85 Volts and 0.36 Amps, Exactly the same that i get measuring between the battery terminals. Therefore it seems that the regulator is leaking everything it's getting from the battery to the frame :)

[motorang]

That sounds reasonable :D
But does not explain why the draw goes away when you switch the ignition off as the regulator always is connected to alternator AND battery.

Cannot help with the diode measurement, as its too electronic for me :D

Only know from experience that Multimeter measurements of resistance are only useful for similar use cases, i.e. high resistance electronics stuff.
The multimeter measures wit nome milliamps and only some volts, while in real life there is a LOT more going on in terms of current, and some more in terms of voltage as well.

Its like checking the water pipes of a house with a syringe. You may not be able to tell if there is enough water coming through for a nice shower.

If NO water is getting through you know there is something wrong. But if some water is coming through you do not know if it is enough.
Same with resistance readings. If the reading is off the spec, the part is likely to be broken.
But if the reading is OK, it STILL may be broken. May fail with voltage peaks, high load, temperature or vibrations.

Andy

[j0epere]

But does not explain why the draw goes away when you switch the ignition off as the regulator always is connected to alternator AND battery.

Well like i said before, the draw goes away when I disconnect the regulator and/or Main fuse. The ignition didn't have any effect. Pardon my shitty paint skills, but looks like my theory holds up.


Fortunately this broken regulator gave me a reason to learn how to read Wiring diagram and I feel that I'm starting to understand how a motorcycle electronics work. Also as a silver lining I can use this leaking REG/REC as a backup, because it does the charging bit well.

Thanks for the help!

[motorang]

i noticed that the current went to "0" when i disconnected either the main fuse(Red wire coming from the starter switch assy) or disconnecting the regulator/rectifier.

Ah you are right, the regulator is connected via the fuse right there.
Good you found it then!

Andy