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Discussion Starter #1
I've suspected I had a battery drain for the last little while and checked into it recently.

I pulled the positive leads off the battery. I have two, the main one, and a separate one for the new Mosfet R/R. Set up my multimeter in series with the leads and battery and noticed a draw coming from the Rectifier lead.

What would potentially cause this? I wired the Rectifier according to the instructions provided. So the positive and ground are connected directly to the Battery.

Is it normal for a Mosfet R/R to draw current?
 

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I don't know exactly how the MOSFET R/R works, but I never did like MOSFET anything. One more reason I lost interest in amateur radio. Kind of like everybody wanting to put LED everything on bikes. What's wrong with regular bulbs? The VN750 came with old technology that works. I know it works, because I have put 150,000 miles on it without a failure.
 

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I've suspected I had a battery drain for the last little while and checked into it recently.

I pulled the positive leads off the battery. I have two, the main one, and a separate one for the new Mosfet R/R. Set up my multimeter in series with the leads and battery and noticed a draw coming from the Rectifier lead.

What would potentially cause this? I wired the Rectifier according to the instructions provided. So the positive and ground are connected directly to the Battery.

Is it normal for a Mosfet R/R to draw current?
No it is not normal for them to be a current draw,do you have the headlight relay jumpered also or did you put it back in the circuit like it was before.the mosfet should only work when ac current is coming into it from the stator ,your new RR may be faulty,it doesn't matter if it is a mosfet or shunt type ,it should not draw current with the key off.

One possible solution is run the battery positive lead thru your ignition switch ,thereby disconnecting it from your battery with the key off.Which should solve your problem if it is working properly otherwise.

I don't know exactly how the MOSFET R/R works, but I never did like MOSFET anything
The same reason a lot of kids won't eat Brussel Sprouts,they don't know what they taste like ,they just don't like 'em
 

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Discussion Starter #4
No it is not normal for them to be a current draw,do you have the headlight relay jumpered also or did you put it back in the circuit like it was before.the mosfet should only work when ac current is coming into it from the stator ,your new RR may be faulty,it doesn't matter if it is a mosfet or shunt type ,it should not draw current with the key off.

One possible solution is run the battery positive lead thru your ignition switch ,thereby disconnecting it from your battery with the key off.Which should solve your problem if it is working properly otherwise.
I have done nothing with the headlight relay yet. Actually since I never had the bike running before installing the new rectifier I'm not sure what the normal headlight function is like. It's off when I turn on the bike, and lights up after the engine is started.

I thought about wiring it through the ignition. But the whole point of wiring it directly to the battery was to have as little resistance as possible. I've also thought about a relay that could get a signal when the key is turned on and allow power to flow.

But my main concern is figuring out why it's drawing current if it's not supposed to.
 

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I have done nothing with the headlight relay yet. Actually since I never had the bike running before installing the new rectifier I'm not sure what the normal headlight function is like. It's off when I turn on the bike, and lights up after the engine is started.

I thought about wiring it through the ignition. But the whole point of wiring it directly to the battery was to have as little resistance as possible. I've also thought about a relay that could get a signal when the key is turned on and allow power to flow.

But my main concern is figuring out why it's drawing current if it's not supposed to.
Your head light as working as it should,that's odd if you didn't use any part of the original harness.If you did use part of the original harness that went to the R/R your current draw may be in the headlight relay which is internal to the JB.



Check this thread out and see if you wired it this way or used any part of the factory R/R harness ,If you did ,you may need to do it like this without hooking up the head light relay to the charging system and jumper the relay at the Junction Box so it will come on as soon as you turn the key on rather than waiting for the engine to crank.Your Junction box may be the culprit instead of the R/R. and if you take the headlight relay out of the circuit until the key is on, you may lose the current draw with the key in the off position.
http://www.vn750.com/forum/showthread.php?t=20056
 

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Discussion Starter #6
Your head light as working as it should,that's odd if you didn't use any part of the original harness.If you did use part of the original harness that went to the R/R your current draw may be in the headlight relay which is internal to the JB.



Check this thread out and see if you wired it this way or used any part of the factory R/R harness ,If you did ,you may need to do it like this without hooking up the head light relay to the charging system and jumper the relay at the Junction Box so it will come on as soon as you turn the key on rather than waiting for the engine to crank.Your Junction box may be the culprit instead of the R/R. and if you take the headlight relay out of the circuit until the key is on, you may lose the current draw with the key in the off position.
http://www.vn750.com/forum/showthread.php?t=20056
Ok, this is odd. I did not use any of the original harness, and I wired everything just as mentioned in that post except for a jumper to the headlight relay.

Without that jumper my headlight should not come on at all, correct? The relay shouldn't be getting a signal unless someone tinkered with it previously.
 

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Since the Mosfet R/R measures the voltage from the output instead of a separate sense wire like the original R/R, it will draw a little bit of current from the battery when the engine is off. But it should not be much - less than 10mA. It should not matter if the bike is regularly used, but will drain the battery if not (winter). How much current did you measure?
 
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