Yet another issue with wiring/battery drain/m.unit blue.

[fabtax]

Hello all,
My name is Fabien, I live in Toulouse (France) and i'm the happy owner of a 1977 XS650 type 447 and a bunch of other vehicules

I've started to rebuild from scratch the electrical part and add a motogadget m.unit blue.
This is at this point that i've started to have issue and battery drain.

When i turn the ignition to on, i can see amps growing from motogadget apps on the ignition wire.

Here is my wiring schema :

I've tested my coils (4.5 Ohms), changed my capacitors, bought a new battery... I'm running out of ideas.

Before modification everything was running fine. Previous owner simplified too much the wiring (No horn, no turn lights, no hi beam), that's why i've rebuilt it

Any ideas ?

Thanks !

 

[Its been a long time]

In the drawing, the M Unit always has power 100% of the time. The key switch does not remove power from the M Unit. Always a small current draw from the M Unit?

Reg/rec is always powered off the battery. Small current draw? (Purpose of the green wire there? Rotor excitation?)

I see no power to the neutral switch.

 

[fabtax]

Hello,
Indeed M.Unit is always powered but as seen into the specs, it's current is above few mAmps. Last week it took less than 3 days to drain my battery.
For the wiring im not sure about the charging system i need to check the reg.

The neutral is connected to my gauge, it is working, my diagrams has some mistakes.

 

[Its been a long time]

Hello,
Indeed M.Unit is always powered but as seen into the specs, it's current is above few mAmps. Last week it took less than 3 days to drain my battery.
For the wiring im not sure about the charging system i need to check the reg.

The neutral is connected to my gauge, it is working, my diagrams has some mistakes.

Thank you for replying. It's not helpful if your diagram has mistakes.

It is also not obvious why the starter switch and kill switch is one item. Maybe that's another mistake?

I suggest to disconnect one part and wait a day. If the battery is still discharging, disconnect another part. Do this until you find the component that is causing the battery to drain. Good luck.

 

[JJames]

Hi Fabien. Welcome to the forum. That's a nice looking XS. I'll leave the electrical questions to those more qualified but you've come to the right place. Best wishes, have fun.

 

[mike in idaho]

Looking at the diagram, I think I would put the main switch in the line from the main fuse to the "bat" terminal of the M unit, that will ensue it's completely "dead", with the key switch off. Also, you might consider disconnecting the rectifier for a few days, in case there is current leakage through it.

 

[fabtax]

Thank you for replying. It's not helpful if your diagram has mistakes.

It is also not obvious why the starter switch and kill switch is one item. Maybe that's another mistake?

I suggest to disconnect one part and wait a day. If the battery is still discharging, disconnect another part. Do this until you find the component that is causing the battery to drain. Good luck.

The starter switch is working as expected, it's a push button. Once for firing, twice push to stop.

 

[fabtax]

Looking at the diagram, I think I would put the main switch in the line from the main fuse to the "bat" terminal of the M unit, that will ensue it's completely "dead", with the key switch off. Also, you might consider disconnecting the rectifier for a few days, in case there is current leakage through it.

This is what im thinking also. But i need to know why when key contact is on, ignition drain my battery

 

[fabtax]

Hi Fabien. Welcome to the forum. That's a nice looking XS. I'll leave the electrical questions to those more qualified but you've come to the right place. Best wishes, have fun.

Thank you !

 

[Its been a long time]

Looking at the diagram, I think I would put the main switch in the line from the main fuse to the "bat" terminal of the M unit, that will ensue it's completely "dead", with the key switch off. Also, you might consider disconnecting the rectifier for a few days, in case there is current leakage through it.

I suspect it's the charging system that's the issue. It seems to me that if the bike has a field excited alternator, then the field coil could be powered up 24x7.

 

[fabtax]

I suspect it's the charging system that's the issue. It seems to me that if the bike has a field excited alternator, then the field coil could be powered up 24x7.

I will take picture of the Reg and the wiring i've made. Thank you for your help !

 

[Its been a long time]

I will take picture of the Reg and the wiring i've made. Thank you for your help !

You have the standard XS650 field excited alternator?

 

[fabtax]

You have the standard XS650 field excited alternator?

I've installed this :

 

[Its been a long time]

I've installed this :

Thank you. Then it's not field excitation that's your problem. Because you don't have it.

Next thing, I would disconnect the red wire between battery and reg/rec. That might diagnose your problem if current is leaking across the reg/rec unit.

 

[fabtax]

Thank you. Then it's not field excitation that's your problem. Because you don't have it.

Next thing, I would disconnect the red wire between battery and reg/rec. That might diagnose your problem if current is leaking across the reg/rec unit.

Thank you for your answer, i will test your proposal and let you know