Dead after killing Mustang

[webbcraft2150]

Ultimate embarrasement. Jr. with his 5.0 kept messin with me on the way home yesterday. Last time he came smokein up beside doin bout 40, I had enough. Snicked er down a cog and dialed "high" on the throttle, he tried but it wasnt happening. Anyway, hes behind me at the light, my XS is happily idleing away, light turns green, I take off at a normal rate, go about 3ft and it shuts down like I hit the kill switch, no electrical at all. I push it into the gas station. Checked all fuses and battery connections (I had just finished making new cables), wiggled wires and still dead. Came back later with voltmeter to do some troubleshooting. This is the weird part, I am showning 15.2volts at the battery and the start solenoid (used two different meters). Engine would crank when I jumped the solenoid but will not run. Am I a victim of the ign switch wire(s) breaking? I guess I have somthing to do this long weekend

[DiverRay]

I would check the Ign. wires first. It;s kind of a pain, but the probable cause. Look at the connectors in the headlight, and then pull the back off the switch and check all the solder connections.
I'm just starting to take my "Daily Rode" down now. I need to fix first AND second gears. This starting in third is OK on the flats, but my driveway is a steep uphill, and the clutch won't last long if I don't fix the tranny.

[chevy45412001]

before tearing

into all sorts of messy things, check the fuses with a test light. both sides of the fuse,i've came across this before fuse appears fine but broken under the tin end( if still using glass fuses that is )also might want to check the wires that go to the fuses,just one month ago had a melt down with a power wire to the fuse block itself was broken but touching the connection so had an ittermitent problem.Just a thought before getting real dirty. Then i would get into pick-up wires and such.

[desert1]

kill switch circuit

check the kill switch circuit wires under the tank as well and there multi plug connections wherever ther is a white wire with a red tracer..........

[Ken Talbot]

Check the main fuse - the in-line one on its own on the opposite side of the bike from the fuse box.

[skids]

After you get it running, check the voltage across the battery again at about 4000 rpms. 15.2 volts seems abnormally high.

Originally posted by Ken Talbot
Check the main fuse - the in-line one on its own on the opposite side of the bike from the fuse box.

[prometheus578]

Skids... I believe, if I'm reading him correctly, that his battery is showing 15.2 volts... NOT running. He says he can get it to crank, but not run. So the battery's been overcharged. Meaning the voltage regulator ist ferschimmelled! What damage could have been done by this abnormally high voltage, I can't say. Usually it just cooks the battery dry. Fried wires? Burnt connections? Brain box? All things to check.

[2fast]

I'm thinking along the same lines. If he has over 15 volts at a resting battery, the battery is toast. Unusual though, you would think it would be low, not high. It should be just over 12.5 at rest. Given that, I would take that battery out, and connect any known good 12 volt (car battery will do) with jumper cables direct to the battery cables. If it starts, measure the voltage output and see if it goes up around 14 when revved and down at idle. It does sound like the reg might be shot to have created this problem, but might be just battery. Any way, it's a cheap and easy test.

[GNEPIG]

.. no disrespect intended towards 2fast but i dont think i would hook up a car battery to your motorcycle, a car battery has too many amps, the amp rating for your cycle battery should only be at 300 cca at best
450cca to 600cca and more, might toast things
.. i would focus on getting the bike running first, then check your charging system.. take your battery to a cycle shop and have them load test it to see if it is good, your battery could have 20 volts dc but if it only has 20 amps, your are not going anywhere
.. if the battery is cranking the bike over at a decent pace when you jump the silenoid then the chances are your battery is not bad, yet.. im thinking fuses or coroded conections would be where i would look first, if there is no power anywhere, start at the new home made battery cables first then work your way towards the front of the bike from there

[2fast]

No offense taken, but I think I am correct. The amperage (as long as it is high enough) does not matter much. Fuses will prevent any overdraw which would generally only occur with a short of some type. I have run many a motorcycle straight from a car battery during diagnosis of problems without any issue whatsoever. I am sure some one other than me can explain it better in technical terms, or else tell me why I am wrong.
Here is what a battery web site has to say:

"9.1) Cold Cranking Amps (CCA)
The most important consideration is sizing the battery's CCA rating to MEET OR EXCEED, depending on the climate, the car's OEM cranking requirement. [CCAs are the discharge load measured in amps that a fully charged battery at 0 degrees F (-17.8 degrees C) can deliver for 30 seconds and while maintaining the voltage above 7.2 volts. "

[Ken Talbot]

Hooking a car battery to dead motorcycle usually won't cause a problem, as long as the the car is not running. When the battery is still in the car and it is running, there's way more chance of delivering more than 12 volts to the bike's system which can cause trouble. Do it with the car turned off, or the car battery out of the car and you should be safe. Just be sure not to crank for too long just because the larger battery has the capacity, or you could overheat and fry the starter.

[Geezer]

Check the plug on the ignition switch. This is a common point of failuer and would case the sysmptonms you describe.

Also high resistance at the ignition switch plug will cause over charging...

Geezer

[strom]

Don't forget the tip-over switch under the gas tank. They were prone to failure. That or killswitch. Maybe TCI, but I doubt it. Hopefully just a fuse.

LP

[webbcraft2150]

It lives!!!

Set up the garage for "surgery". Even though I had checked all the fuses visually, I thought I would check with the meter. Started at the main fuse first, looked good, metered it, no continunity. Replaced fuse, turned the key and it fired right up. I figured this was either going to be a 5 minute or 5 hour fix, I lucked out and got the five minute fix. I have owned this bike for over 16 years and have never replaced that fuse. It was even a "Stanley" which leads me to believe it was the orginial. Charging system at 14.7 at 4k, 12.8 with engine off, still scratching my head at that initial 15volt reading. I used a different meter this time. Whats the chance of two meters being off
Thanks for all the tips guys. Next project, fuse box replacement and replace the main with the ATO style.

[prometheus578]

"Sure... she looks good, but doesn't put out!"

How often have we all said that one?

Started at the main fuse first, looked good, metered it, no continunity.

And how often have we all said THAT one? Have had fuses look good, have continuity from end to end, and still no juice. Tend to forget about the 25 years of nonconducting tarnish on the clips that hold the fuse in place. Scrubbed them with a rifle bore brush, put fuse back it, no probs.
I'd carry a few fuses in your leather jacket till you clean all the connections and replace the fuse box. I don't think the old girl's done with you yet. I also believe that the readings from your other two voltmeters were correct at the time. Clean all electrical contacts and grounding points. Your fuse could have diesd from old age... or it could be something more.