Confused with 1986 VFR 700 electrical issue

Hello all,
I was preparing my bike (bone stock 1986 VFR 700) for this summer so I decided to go head and replace the R/R that was on it's way out. Went with a Ricks unit and it worked fine on the test ride. I have always noticed after approximately 5-10 attempts to start (5-10 seconds duration each on a freshly charged battery) the battery goes flat, so I suspected parasitic draw. Advance to this afternoon, I go to fire my bike up to ride to dinner and the lights come up like normal, the fuel pump activates for 5 seconds straight (not normal) and suddenly the static battery voltage drops from 12.68v (key off) to 1.05v and falling with the key switch on. I check for parasitic draw by reading voltage between battery negative terminal and motorcycle ground cable and I get 12.5v discharge with the key on, 0v discharge with the key off. I would think short to ground but I have not blown a fuse yet. I trace continuity back to the starter relay and find continuity between the green wire with red stripe and the two red wires with white stripes. According to my manual that is the neutral indicator light and the R/R wiring respectively. I check for burned connectors and find slight melting at the red starter relay cover connector, I disassemble it and find no contact between spade connectors. In a rush I tried to disassemble my starter relay, lesson learned DONT TRY IT, it is now trash. So any ideas on where to look next? I want to check the key switch wiring but I ran out of time. Is this a common issue?

Sorry if it has been covered already or if this is in the wrong sub-folder. I searched but had no luck. Thanks in advanced.

 

First thing, how old is the battery?

 

Battery is less than 6 months old, plus it's been properly maintained with a battery tender since new. Bike started great two days ago and ran well.

 

let me get this straight....you have 12v drop on your ground cable when it is connected?

 

Sort of, I checked it this morning and the bike switched on like normal, lights up and static voltage dropped to 12.1v (from 13.1v after disconnecting from my battery tender) with the key on. I cycled the key several times and wiggled the wiring by the starter relay and the ignition switch and noted no additional drop. So, since I broke the small copper wires that make the starter relay work I touched the starter cable (which was disconnected from the relay since the relay has failed closed) to its terminal on the starter relay and got the huge voltage drop again! Lights went out, battery voltage dropped from 12.1v to 1.05v.

 

Regardless of the age of the battery, I would have it tested just to be sure. Nothings says the age of a product is a guarantee that it was made error free or free of any defects.

 

Valid point, I don't have a load tester, what would you suggest? Ok, just went out and swapped the battery for another. Bike acts just. Like normal, lights up, horn honks, engine starts and runs great, charging at 14.25v at idle! But I disconnected the negative terminal and repeated the parasitic draw test with the key off and it is drawing 13v now? Wth is going on?

 

unplug the starter relay and see what happens, sounds like an issue ine there, betting your draw goes to close to 0 then

 

If you are running a parasitic draw test, you need to be measuring current, not voltage.

Put you meter on the 10A scale and run test, with key off current should be very low, if you have a clock.

With key on, current will jump up, not sure what it should read for your bike.

A battery in good charge should read around 13 volts, your charging voltage is OK.

 

Most auto parts stores should be able to test your battery. i.e. Auto Zone, O'Reilly, Pep Boys, etc.

 

Ok, thanks for the suggestions. I'll try the current check when I get home from work. I'm beginning to suspect a
bad battery.

 

When measuring current, meter is in series in the circuit. Used only for low current, less than 10 amps.
When measuring voltage meter is in parallel, like put your leads on battery terminals.
When you measured 13v between battery and ground, the ground became the positive terminal through whatever load there was, so 13v would be correct.
Hook up you battery, put the meter across terminals, note voltage. Turn on key and lights, note any drop. Does it drop much, or slowly? Have battery tested.

 

You guys are right, voltage is not going to measure draw, it has been a few years since mechanics school. Plus my meter has a blown fuse so I knew I couldn't measure amperage. I'll pick up a fuse on my way home and try the CURRENT draw test the proper way. Plus I just remembered over the winter the battery in question was discharged to zero by a faulty R/R, I recharged it and it showed 12.6v so I suspected it was ok, now when using that battery I get a nasty sulfur smell from the battery, indicating plate sulfation has begun? The battery that worked was the old battery that came with the bike when I bought it in 2010, albeit charged it worked great.

 

all i can say is e=ir to find load boys, just saying

 

1986, analog instruments, no clock, right? Shouldn't be any drain on battery while off.

My 03 has a clock and digital instruments, so there is a couple milli-amp drain in the off position.

From the sounds of it, I'd just get a new battery, and get ready for spring!

Check all your connectors for even mild corrosion, that will not pass proper current, but can fool you on a voltage reading, especially the stator connector.

View attachment 25914
Take a small emery board, cut sides down to 1/4" wide, peel off coarse side and insert into female stator connector, turn it around and do other side.

Cheap easy way to burnish connectors and get rid of mung.

 

Great idea on the emery board! I normally use a point file but it is on the thick side. I can't wait to get home and check out the battery now, it's getting to be riding season here in NC.

 

Ok, I just got in from my 40 degree ride and the bike performed flawlessly using the old battery, regulator charges and all seems well. I guess I'll have to give the "borrowed"'starter relay back to its rightful owner eventually... Thanks for your help and expertise, after all it turned out to be a bad battery.