[Jeffsg605]

I went to start my 93 vs1400 the other day and it was dead. I took out the battery to find the negative terminal was melted and battery was at around .2 volts.

I did some diagnosis and found a short between the negative battery cable and the positive post on the starter. I replaced the starter but I'm still getting continuity between the negative battery terminal and the positive post on the starter. I know the cable from the solenoid to the starter is not shorting.

Any ideas?

Thanks!

 

[WintrSol]

The starter motor will look like nearly a short from its positive connection to its negative connection, because it is a large electric motor that can draw 40A or more when operated. The only time that comes into play is when the starter relay applies battery positive to it, which should run the motor. A battery terminal usually melts when it has a high resistance, either between the cable connected to it, or because of an internal crack; when that high current through the starter motor tries to pass through it, that resistance generates a lot of heat.

You could have a load on the battery outside the starter motor; for example, the starter relay could be stuck on, or a wire in the harness, on the positive side of the battery, shorted to ground, causing the battery to drain. With the battery disconnected, try measuring from the positive battery cable to ground (engine case, e.g.) when the key is off. Still, a load like that wouldn't melt the battery terminal, unless it also has a high resistance causing heat.

Do you have a service manual or wiring diagram?

 

[Jeffsg605]

The starter motor will look like nearly a short from its positive connection to its negative connection

Interesting. I did not know this. So its normal to have continuity between the negative cable and the positive of the starter?

You could have a load on the battery outside the starter motor

There were no blown fuses. I can't seem to find a short although there was sparking when I connected the negative battery cable to the battery that seemed excessive.

There wasn't a lot of dirt/etc. between the negative cable and the battery but I can't think of what else it could be. This is the wiring diagram.

I'll make sure the negative battery cable that attaches to the frame is clean as well. Otherwise is it possible that the battery could have been bad? Everything else seems to check out okay.

 

[WintrSol]

Interesting. I did not know this. So its normal to have continuity between the negative cable and the positive of the starter?

The starter motor is large coil of wire, connected from its positive terminal to the engine case; the battery negative goes directly to the case, too.

There were no blown fuses. I can't seem to find a short although there was sparking when I connected the negative battery cable to the battery that seemed excessive.

There wasn't a lot of dirt/etc. between the negative cable and the battery but I can't think of what else it could be. This is the wiring diagram.

I'll make sure the negative battery cable that attaches to the frame is clean as well. Otherwise is it possible that the battery could have been bad? Everything else seems to check out okay.

Was the sparking with the damaged battery, or new? And, was the key on or off? With the key off there should be no sparks at all, unless there is a leak from the positive side to the frame ground. Did you have the battery dropped out of the battery box before you attached the negative cable, or was it in its normal location? I'm concerned that the positive cable has damage, and can short to the frame. The proper procedure on this bike is to disconnect the negative terminal, make sure it can't make contact, then disconnect the positive, followed by opening the battery box and lowering the battery. Some extend the wires so they can drop the battery before disconnecting the cables, which can lead to various shorts.

I have seen quite a few batteries over the years that are broken inside, either because the terminal was bumped hard enough, the cable was yanked, or just a defect. Of course, that is really only a few compared to how many batteries I've handled over the years.

 

[Jeffsg605]

Here is a quick run down of what happened.

Earlier this summer I replaced the battery. It was old and not holding a charge. I rode the bike maybe 2 or 3 times in the next few weeks. On the last ride, it started misfiring past half throttle on the way home. I parked the bike and didn't touch it for a few weeks. I went to start it again and it was dead. This is when I found the battery with the melted terminal. So i got a couple rides with it between changing the battery and the battery somehow draining.

To answer your questions:

Was the sparking with the damaged battery, or new?

Brand new.

And, was the key on or off?

Key off

Did you have the battery dropped out of the battery box before you attached the negative cable, or was it in its normal location?

Yes, I dropped the battery box. Really the only way to change the battery on these bikes.

I'm concerned that the positive cable has damage, and can short to the frame.

I pulled out the DMM. There is no continuity between positive battery terminal and frame. Nor is there between battery side of the solenoid and the frame. When I disconnect the hot cable from the starter, there is no continuity between the starter side of the solenoid and the frame. No fuses are blown. This is why I'm wondering if it was the battery that is defective. I assumed it was a short too but I can't seem to find anything indicating that. That's why I'm thinking it was a defective battery.

I'll thoroughly check the positive and negative cables again. Maybe even remove them and clean the terminals. Every google search I'm reading seems to point the cause of a melted terminal to dirty connections. I'm not convinced that's what caused mine but I'll give it a shot.

Any other ideas? I appreciate the help so far!

 

[WintrSol]

Yes, I dropped the battery box. Really the only way to change the battery on these bikes.

The stock configuration requires disconnecting the cables first, then opening the bottom of the battery box to let the battery down.

I pulled out the DMM. There is no continuity between positive battery terminal and frame. Nor is there between battery side of the solenoid and the frame. When I disconnect the hot cable from the starter, there is no continuity between the starter side of the solenoid and the frame. No fuses are blown. This is why I'm wondering if it was the battery that is defective. I assumed it was a short too but I can't seem to find anything indicating that. That's why I'm thinking it was a defective battery.

I'll thoroughly check the positive and negative cables again. Maybe even remove them and clean the terminals. Every google search I'm reading seems to point the cause of a melted terminal to dirty connections. I'm not convinced that's what caused mine but I'll give it a shot.

Any other ideas? I appreciate the help so far!

If you can lower the battery out of the box before disconnecting the cables, the cables have been extended. There is access to the terminals through openings on either side; the negative side (RH) has/had a plastic cover, while the positive side is visible above the regulator. There are two bolts that let the bottom door of the box swing out from under the battery, which will fall if you aren't ready. BTW, this is most easily done with the rear wheel on a 2x4, or the bike on a lift, because of how low the bottom of the box normally sits.

You could have an intermittent short on the positive cable, which only shorts when vibration or bouncing of the bike while riding causes it to make contact, even though you read open with your meter. If the cables have been extended, you will have to examine the positive cable carefully, especially where it was spliced to the original wire. Another possibility is a replacement battery that doesn't fit snugly in the box, and can move around and short the terminals.

 

[Jeffsg605]

I see what you mean about the cables now. Yeah, I guess they must have been extended. I'll look them over again. The battery does sit very snugly but I'll look into that as well. Thank you so much! I'll let you know how it turns out.

 

[Jeffsg605]

Well I removed the positive and negative cables and the insulation wasn't broken or anything like that. I took a wire wheel to the ring connectors crimped on the ends. Then reinstalled them and had zero spark with the negative battery terminal. Looks like that was the fix, thanks a lot!

 

[WintrSol]

Good you have it fixed. I always use DeoxIt on my connectors and terminals, as it cleans any oxides from them, and will keep them clean longer.

Now you know about the wires, you also know to take care pushing the battery back up, so as not to create any breaks in the insulation.

Now you need to go for a ride!