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V11 ground vs battery tender

bradleyj20

Just got it firing!
Joined
Sep 14, 2013
Messages
2
Location
santa monica
I recently installed a new yusa battery in my 2003 V11 Sport. I connected the battery tender to it for the first time, and stupidly, the tender was plugged in and fully connected when I connected the positive of the battery tender to the positive of the battery. (i'm swearing that I had the polarity correct). It immediately started cooking the smaller ground wires on the bike and I disconnected it within 1 to 2 seconds. The smaller grounds, including the one from the ECU burned insulation slightly, but all wires appear in tact. I have electrical tape around the portions that melted a bit, but everything appears to be working fine, and the bike appears to run just fine.
Was my only problem connecting the tender while it was plugged in (it's been a while, but I don't remember having to care so much about the process of hooking up the tender), or did I do something stupid that I am not aware of, or could there be something wrong with the tender?
Any thoughts that more extensive damage may have been done that I am not aware of?

Any light that can be shed is appreciated.
 
Yes you should not plug the tender into the wall first, but what you did shouldn't fry any wires. The darn thing only outputs 1.25 amp. That shouldn't fry any wires. Are you sure the polarity was correct? but the tender should have a protection circuit to prevent damage. I'd say there is something more going on than what you have relayed. Now, does the bike still run OK in spite of the incident?
 
The bike idles ok, and revs through the rpm range smoothly at rest, but I haven't taken it on the road yet. I hear what you're saying about polarity. The one and only time I crossed poles jumping a car, it reacted exactly like this, immediate smoking of wires in the alternator (had to buy a new one). I was staring at the clamps on the tender when I hooked it up, and was certain I was putting red positive from the tender to positive on the battery, but I suppose there could have been brain fade. Could the tender be damaged? Maybe the pos/neg clamps on the tender touched while plugged in, but I don't know if that would hurt it.
 
I don't think you did anything wrong by having the tender hooked up, it must have been something else caused the melt down.

Here's a couple of scenarios
If the main battery ground is not connected properly the starter current (or any other current for that matter) finds it's way back through the small grounds e.g. the one on the Voltage regulator, this small ground can get red hot melting the insulation off adjacent wiring shorting those to ground also until it's all one grounded mess. I'm sure more than one Guzzi has gone into melt down this way especially the models with unfused wiring to and from the ignition switch.

You may have had a loose main ground and an accidental short on the positive side, that's about the only way you can overheat the small grounds other than the heavy start current. (If the main ground is in place there will be no Voltage across the smaller ones to cause them to heat)

Another member I helped had accidentally shorted a wrench from the positive terminal to the ECU, that melted it's ground wire shorting other wires to ground where it entered the loom.

I advocate removing the ground wire from the regulator and connecting a small jumper from the regulator case to a timing cover bolt, this removes the alternate path. and has the added bonus of improving the charging.

The V11 Sport and like bikes had the ground wire clamped under the seat release lock, this can easily work loose. It should be re-located to a more secure bolt.

If your bike seems very sluggish while cranking check the battery ground wire. Another way to check is measure the Voltage from battery negative to the chassis while cranking, it should stay close to zero.

Always disconnect the battery negative first when removing the battery and likewise connect the negative last when replacing it, that way if you accidentally short the positive to chassis no harm is done.
 
My V11 has developed sluggish cranking. Is the ground wire from the neg battery pole the one I should check and is it the one that is behind the seat lock? I wanted to do this but had no idea where the wire from the battery was grounded to the chassis. Thanks!
 
Behind the seat lock is a silly place to connect the main ground (I must admit mine is still there)
Sluggish cranking is one symptom of a bad ground, the next symptom is magic smoke emitting from the loom under the tank as the starter current finds it's way back to the battery via the small ground wire attached to the regulator case. I know of at least two bikes where this happened. The real problem is the red hot ground wire melts into other wires making a right mess.

I highly recommend cutting the black wire off the regulator case and replacing it with a short jumper to a timing cover screw, the engine and main ground cable is a much better path, there should be only one route for the heavy start current.
The result will be better charging and no chance of a melt down.
All the current flowing from alternator to the battery has to find it's way back to the regulator case.

Another ground that can cause a problem is the case ground on the V11 Sport ECU. If you accidentally short Positive to the case with a wrench while disconnecting the battery this tiny ground will melt into the loom also

Remember - always disconnect the Negative first, connect it last

Roy
 
georgialemans said:
My V11 has developed sluggish cranking. Is the ground wire from the neg battery pole the one I should check and is it the one that is behind the seat lock? I wanted to do this but had no idea where the wire from the battery was grounded to the chassis. Thanks!

You should check the ground ASAP, if it's loose you run the chance of serious loom damage if not a fire.

http://s1304.photobucket.com/user/Kiwi_ ... ic%20Smoke

The first picture sent me from a V11 Sport owner shows how the regulator ground wire shed it's insulation while starting.
The next two are mine before and after, the schematic tries to explain what can happen.
I'm not saying you have to relocate the ground or chop the one of the regulator but for guzzi's sake keep it tight.
 
In addition to the facts above, don't overlook the fact that the V11S puts the positive battery terminal perilously close to the ECU and many other easy-to-ground parts. My speculation is that the the positive clip of the tender was either touching the ECU, or was grounded to the frame. It happened to me once when I was trying to use a larger clip on an older charger. Just FYI. Best to just bolt the quick-release pig-tail supplied by most chargers these days.
 
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