Parasitic battery drain troubleshooting

[Steph]

I started troubleshooting my parasitic battery drain and I'm not getting very far, I'm poor at electrical stuff. What I've done so far:
-tested battery, fully charged, only12.4v (bought a new one and it's in its way)
-the drain is approx .25 amps between the negative battery  terminal and the negative wiring loom. I believe that figure should be .05 max (correct?)
-removing the fuses one by one, fuse #1  30amp is the culprit.
-checking the 30amp circuit, unplugged most plug no drop in the .25 amp reading. When I ungrounded the regulator the amperage goes down to .08 and the generator light glows. (The key is out of the ignition)
-the regulator has wires that I haven't tried to disconnect.

Started to rain, stopped for a while.
Any troubleshooting advice?

[KiwiKev]

I started troubleshooting my parasitic battery drain and I'm not getting very far, I'm poor at electrical stuff. What I've done so far:
-tested battery, fully charged, only12.4v (bought a new one and it's in its way)
-the drain is approx .25 amps between the negative battery  terminal and the negative wiring loom. I believe that figure should be .05 max (correct?)
-removing the fuses one by one, fuse #1  30amp is the culprit.
-checking the 30amp circuit, unplugged most plug no drop in the .25 amp reading. When I ungrounded the rectifier the amperage goes down to .08 and the generator light glows. (The key is out of the ignition)
-the rectifier has wires that I haven't tried to disconnect.

Started to rain, stopped for a while.
Any troubleshooting advice?

The regulator should be disconnected with the ignition turned off to stop this happening. What bike is it , Roy is the man amongst others here.


Sent from my iPhone using Tapatalk

[Wayne Orwig]

Sounds like you pretty much narrowed it down to the regulator/rectifier. I have seen the epoxy crack and let water in. 

[Kiwi_Roy]

I think this is your schematic
http://www.thisoldtractor.com/guzzi007/schematics/2002_Stone.gif
A new battery is not going to fix it, you have to find out where that 1/4 Amp is going.

Unplug the regulator, it may be as Wayne says.

BTW, congratulations on knowing how to connect the meter and read the current.
According to the schematic that circuit also goes to the ignition switch so be prepared to unplug that also near the headstock, a 4 pin connector)
The switch shouldn't pass any current turned off but then neither should the regulator.
Please post back what you find, this is a new problem for me.

If you haven't cleaned the switch in a few years it might be a good opportunity, it's very easy to get off, just two Phillips screws from under and the back clips off, white contact plate tilts out. Use Vaseline to re-lube the switch, no fancy grease. When you put the switch back together fix the wires to the cover so they don't flex at the solder joint or they quickly snap off.

Update:
           If the switch is allowed to get too dirty you may eventually have starting issues

[Steph]

I think this is your schematic
http://www.thisoldtractor.com/guzzi007/schematics/2002_Stone.gif
A new battery is not going to fix it, you have to find out where that 1/4 Amp is going.

Unplug the regulator, it may be as Wayne says.

BTW, congratulations on knowing how to connect the meter and read the current.

Have you added any electrical accessories?

No extra accessories.
I'm trying to fix the drain to avoid running down a new battery, I knew I had a drain and disconnected the -ve screw after every ride, home made switch isolator!

If I unplug the yellow wires and the amps drop - is tit the alternator?

[Kiwi_Roy]

That is unusual
With the wires unplugged do you get an Ohmeter reading to chassis on the alternator side?

The alternator is quite simple, take the cover off and look at where the wires are soldered on.

[Steph]

Here is the UK '02 Cali Stone wiring from owners manual

[Kiwi_Roy]

OK, your diagram is not like Carls at all the regulator is not connected to the ignition switch so you have it narrowed down to the regulator or alternator.

I don't understand why the current drops when you unplug the yellow wires (alternator) I think there must be a leakage to ground inside there, its a simple winding that should have no connection to ground.
Does it drop when you only disconnect one yellow?

I also don't understand why current can run back into the red wire, inside the regulator there are diodes that should block it, unless you have the battery reverse polarity.

Was the bike charging normally?

[Steph]

OK, your diagram is not like Carls at all the regulator is not connected to the ignition switch so you have it narrowed down to the regulator or alternator
I don't understand why the current drops when you unplug the yellow wires (alternator) I think there must be a leakage to ground inside there, its a simple winding that should have no connection to ground.

I didn't think the diagram was the correct one, the fuse amperage being different too.

-I did not unplug the yellow wires- I was asking a what if question to figure out what it would mean.

I did unplug the ignition loom plug and it still registered .25

Btw, after the battery being disconnected for a while, the first reading is .45 and then slowly goes down to .25 and stabilise there.

[Steph]

The bike charges normally, but strangely higher with the lights on.
13.7 with the lights off, 14.04 with lights on

[Kiwi_Roy]

It's probably a water issue as Wayne says he's seen it before.
Current should not run back into the red wire, there are diodes that should block it to 0.000mA
I have seen regulators with major issues around these 2 diodes, melting and arcing

I thought you said the current dropped when you unplugged the yellow wires.

[Steph]

It's probably a water issue as Wayne says he's seen it before.
Current should not run back into the red wire, there are diodes that should block it to 0.000mA
I have seen regulators with major issues around these 2 diodes, melting and arcing

I thought you said the current dropped when you unplugged the yellow wires.

Sorry, miscommunication on my part here, I have not unplugged the yellow wires (at all) or any wires directly connected to the regulator ( hard to get at, unsure if there were plugs under the electric tape or hard solder-then it started to rain)

I don't understand your point about the red wire with current running back

[Kiwi_Roy]

I think you said the current dropped to zero when you pulled the 30 Amp fuse
The Diodes inside the regulator should only let the current come out of the regulator towards the battery and not go from battery to regulator (only go one way)

Here's a simple sketch which also shows how to test the diodes

DO this test with the regulator disconnected from the battery, you need to access the yellow wire connections.
With the multimeter leads connected the other way it should read open circuit the same as not connecting the leads.
The multimeter has to have the diode test mode, if not use a lamp and some sort of power supply or battery.

[Steph]

I think you said the current dropped to zero when you pulled the 30 Amp fuse
The Diodes inside the regulator should only let the current come out of the regulator towards the battery and not go from battery to regulator (only go one way)

Here's a simple sketch which also shows how to test the diodes

Yes, the multimeter goes from .25 to 000 when I pull the 30 amp fuse.
Let me digest this diagram...

...OK...I'm not confident enough to hook up the multimeter as per the diagram.
Red battery lead on the multimeter to an unplugged
Regulator individual wire?

[Kiwi_Roy]

The key is the two diodes at the top, they should only let current flow out, not back. That's the area I have seen several regulators fail.
But try unplugging the yellow wires first one then both to see if the current drops, that will give us further info.

Also please confirm the bike runs normally, current can run backwards if the battery is in backwards but the bike shouldn't start. I have seen a couple of owners put the battery back wrong after a winter layoff.

[Steph]

The key is the two diodes at the top, they should only let current flow out, not back. That's the area I have seen several regulators fail.
But try unplugging the yellow wires first one then both to see if the current drops, that will give us further info.

Ok, will give it a go. It's dark here and not garage...

[Kiwi_Roy]

Is it parked out in the weather?
That would add more weight to Wayne's idea

[Steph]

Is it parked out in the weather?
That would add more weight to Wayne's idea

Yes, but with a heavy cover.

Unplugged the yellow wires, no difference, .29

[Steph]

Also please confirm the bike runs normally, current can run backwards if the battery is in backwards but the bike shouldn't start. I have seen a couple of owners put the battery back wrong after a winter layoff.

The bike runs absolutely fine, but because of the parasitic draw if I leave the battery connected, it will get discharged after a while

[Steph]

I think all the info is pointing at the regulator. -I'll just buy one and install it myself.
Unless I'm missing something obvious.

Last checks from regulator:
Yellow unplugged : .31
Dual white/something unplugged: .31
Red unplugged:  0.00 !

[Kiwi_Roy]

Yes I'm coming to that conclusion also

Consider going with an after market direct connected type, they don't rely on the headlight circuit but on the other hand have a very small current draw, my Electrosport is about 0.3 milliamps.
Find one that other Guzzi owners are using in your location.

[Steph]

Yes I'm coming to that conclusion also

Consider going with an after market direct connected type, they don't rely on the headlight circuit but on the other hand have a very small current draw, my Electrosport is about 0.3 milliamps.
Find one that other Guzzi owners are using in your location.

Ok, thanks for all the advices all.

Considering the bike is an '02. The Guzzi part hasn't done too bad.
I can get used one for £63 with 6 month warranty or new for £136.
I guess new would be the sensible way to go.

[Kiwi_Roy]

Considering the bike is an '02. The Guzzi part hasn't done too bad.

Fair enough, looking at the schematic you posted the voltage reference looks very good, battery - fuse - relay - regulator

My 01 had two relays in series passed the headlight current thru the normally closed start relay so the Voltage reference was quite flakey which put a strain on the regulator.
Actually I reckon the Ducati Energia is a good design if a bit dated, its the Guzzi wiring that lets it down, I wonder why yours failed.  I will send you a PM

[Steph]

Fair enough, looking at the schematic you posted the voltage reference looks very good, battery - fuse - relay - regulator

My 01 had two relays in series passed the headlight current thru the normally closed start relay so the Voltage reference was quite flakey which put a strain on the regulator.
Actually I reckon the Ducati Energia is a good design if a bit dated, its the Guzzi wiring that lets it down, I wonder why yours failed.  I will send you a PM

Thanks, I've updated the resolution of the schematic for better reading.
I should have the parts by next weekend and will update you.

[Wayne Orwig]

If I unplug the yellow wires and the amps drop - is tit the alternator?

I would be nearly impossible for the actual alternator to cause such a problem. The diodes should block anything like that.

[Steph]

I would be nearly impossible for the actual alternator to cause such a problem. The diodes should block anything like that.

Thanks Wayne.

To clarify my poorly written question (from my iPhone..) i meant:

"If one were to unplug the yellow wire from the regulator (connecting to the alternator) and then the amp reading dropped from .25 to zero, would this mean that the problem is with the alternator and not the regulator?"

[Kiwi_Roy]

No it would mean you had a fault in the regulator and a ground fault in the alternator. The alternator is not connected to ground and the regulator should not allow current back in.


Sent from my shoe phone!

[Steph]

Quick update, I received the new regulator today.
Tested the old one first and the parasitic draw was .27 amp.
Installed the new one, it registered  .01 for a moment and the 0.00 
All good then, problem solved.
Bike runs great

[Kiwi_Roy]

The bike charges normally, but strangely higher with the lights on.
13.7 with the lights off, 14.04 with lights on

Stephan,
              I didn't notice that post before, since it's quite interesting I will answer it now, this is how it happens.
The regulator senses the Voltage after the headlight relay about half way along the tank. There's some resistance between the battery and the point it senses (relay base and relay contacts - for discussion sake let's say 0.15 ohms)
With the lights Off there is no Voltage drop so the regulator sees the true battery Voltage. 13.7
When the lights are On drawing 5 Amps there is now Voltage drop  5 x 0.15 = 0.75 Volts drop
So the regulator thinks the battery is low by 0.75 Volts and increases the charging until it sees 13.7 Volts again and your battery ends up at 14.4
I don't know if this was a deliberate design or just a screw up.

If you add headlight relays powered direct from the battery or an aftermarket direct connect regulator you lose this unadvertised feature.

I have seen the Voltage drop on my bike reach 1.0 Volts after sitting all winter. Reseating the relays dropped it back down to ~0.6 Volts.
I have a theory this is what causes the regulators to fail. As the Voltage goes up the current goes up exponentially until the diodes melt.

We don't notice the lights On / Lights Off difference here in Canada because our Guzzis don't have light switches, the lights are always On


I'm glad you were able to fix the parasitic draw problem.