ECU parasitic drain Moto guzzi v7

[RubenvT]

Hey all,

I've been having battery issues with my moto guzzi v7 2014. After some testing with the multimeter i've found that fuse E is drawing about 50 mA. Fuse is the MIU G3 Control unit.
The thing that I don't understand is that the parasitic drain just started out of the blue. The only thing I had done was install crash bars and handlebar risers. Then didn't ride for a while and the battery was severely drained.
I checked the battery to make sure it wasn't bad and then went to multimeter testing.

So does this mean I should buy a new ECU? Any advice or things I should look at?
I'm thinking of taking off the crash bars just to make sure they aren't somehow causing the issue, although the chance is slim.





Cheers,
Ruben

[Kiwi_Roy]

I will check mine ASAP,
Its probably just there to maintain the ECUs memory.

http://www.thisoldtractor.com/guzzi007/schematics/2013_V7_Series.gif
I have a 2014 V7III Special
I just measured the fuse E on mine at 0.1 mA  (105 microamps o be exact)
So you definitely have a problem there.

Besides feeding +12 to the ECU it also powers up the Pull Up resistor for the clutch input, it made no difference to mine when I pulled the clutch lever but try this on yours also.

[RubenvT]

Thanks Kiwi! Was your motorcycle off for a while? Maybe it drops from 50 after a while.

I'm also not sure what an acceptable amount of parasitic draw is, I've read different things online.
I also found this post on it: https://wildguzzi.com/forum/index.php?topic=105400.0
SmithSwede has around 42mA on his guzzi. If that is a normal case mine is not too far off but still higher.

[Kiwi_Roy]

I last rode around Noon yesterday
50 milliamps is 5,000 x what I read on mine sum ting wong
http://www.thisoldtractor.com/guzzi007/schematics/2013_V7_Series.gif
can you unplug the ECU to make sure it's not some other wiring fault?

[Kiwi_Roy]

Is there anything else you would like me to try?
50 milliamps is a lot to draw, does it change at all, or dead steady?
Try unplugging the ECU
I have a lot of experience with Hi Tech electronics, I worked as an Instrumentation Technician (Industrial Control Systems)

[Kiwi_Roy]

I did some further testing, with my meter replacing Fuse E
Turn key On, the current rises to ~550 milliamps (1/2 Amp)
Turn key Off, the current holds at ~550 for 14.5 seconds then drops down to normal.
I think this current is something to do with the test sequence and may drive the clocks back to zero when the key is turned Off.

[kingoffleece]

It started after your work.  My guess is that a wire or connector, possibly a solder joint got nicked somehow.
Time to start chasing it all down.

[RubenvT]

Can I do the mA measurements with the ECU disconnected? Or did you mean just disconnecting and immediately re-connecting it?
Thanks for helping Kiwi, I think it's clear that the drain is way too high. The drain is steady at 54mA.

I'll also recheck the wiring from the handlebar risers, already saw that the wire running to the clutch was tight (not the clutch itself but the one also shown on the diagram).

[RubenvT]

I've solved the problem! The culprit was indeed the clutch switch. I found a comment from Sib in another post mentioning 55mA drain on the clutch switch. This is so close to my 54mA drain that it couldn't be anything else.

When I had installed the handlebar risers, I re-routed the clutch cable by disassembling the top lever. When I re-installed it, I didn't pay attention to the clutch switch and it had come out quite far. The lever didn't push it back in but pushed it to the side (see pictures). That's why the circuit stayed closed and was continuously draining the battery. (The switch apparently works allows you to start the bike in gear, when the clutch is pulled in. A safety feature.).
I molded the switch back to a size that it could move freely and reinstalled.

After measuring the mA is now around 1.27 
Thanks for the help guys!

[Vagrant]

It's almost always something we F'd ourselves.

[Kiwi_Roy]

Is that the switch you are holding?
Picture 3

 

[RubenvT]

Is that the switch you are holding?
Picture 3

Yep... It was crushed pretty badly. I was able to get it back into shape with some pliers. In this picture it's pretty far out of the socket.

[JHBettsSr]

I've solved the problem! The culprit was indeed the clutch switch. I found a comment from Sib in another post mentioning 55mA drain on the clutch switch. This is so close to my 54mA drain that it couldn't be anything else.

When I had installed the handlebar risers, I re-routed the clutch cable by disassembling the top lever. When I re-installed it, I didn't pay attention to the clutch switch and it had come out quite far. The lever didn't push it back in but pushed it to the side (see pictures). That's why the circuit stayed closed and was continuously draining the battery. (The switch apparently works allows you to start the bike in gear, when the clutch is pulled in. A safety feature.).
I molded the switch back to a size that it could move freely and reinstalled.

After measuring the mA is now around 1.27 
Thanks for the help guys!

Wow, good catch. That's something we can all look for now.