| Author | Message | ||
     Gentleman_jon |
Seems like nothing can spoil one's day quite as much as the sudden arrival of an intermittent short circuit. Am I right? Of course the problem is that if you are lucky enough to be able to recreate the short from time to time, it blows the fuse before you can really track it down. Terribly annoying, correct? My twin brother Steve gave me a great tip which helped my track down a short in my Key switch circuit that was driving me positively crazy. What he suggested was that I hook up a 12 volt bulb to a blown fuse, and then plug it into the offending fuse slot. The trick is carefully cutting open the fuse and then then soldering a wire to each terminal, which is then connected to the 12volt bulb. When one has recreated the conditions that cause the short, the bulb will glow very brightly. Otherwise it will hardly glow at all.  That way alternatives can be eliminated one by one until the short is located.  This shot shows the tester plugged into the fusebox of a XB12S with an R tail. Perhaps all you old shop hands out there already know about this trick, but I did not. | ||
| Diablobrian |
Sometimes the old low tech solutions are still the best, and this is one of those solutions. | ||
| Firebolteric_ma |
when i use to do hvac and we encountered problems that would not be there while we were looking at the unit but once you leave the problem would return, we would put a little unit called a "tattle tail" in the circuit to help find out where it was.(usually one for each circuit to help pinpoint the circuit) once the unit acted up these little tattle tails would trip and a little red button would pop(much like a perdue chicken popper thing). they worked very well at finding the source of the problem. seems you are on the right track w/ the bulb design. nice idea! | ||
| Bake |
Great idea, so what was causing your short? | ||
| Gentleman_jon |
It was just the kind of thing that drives you crazy. Brian, (LoneXB), had recently installed his old R tail on my bike, and we did have one or two little electrical problems, mainly due to installing the tip over switch incorrectly. So when the bike suddenly died whilst on the road, I assumed that the problem was somewhere in the new tail installation. However, as soon as I installed a new fuse, the bike would work, and no amount of pushing and pulling on the electrics in the tail would cause the fuse to blow again. So I would put it all back together, and it would run fine for a few days or a week, and then all of a sudden -- no power at all. Finally, I noticed that by turning the handle bars to the left hand lock, the fuse would blow. I had been searching for the problem at the wrong end of the bike!! Sound familiar? Anyway, I attached the tester as brother Steve had suggested, and was able to determine that the short occurred in the middle of the arc of turning the bars from lock to lock. Every time. It just seemed like it was hard left lock, because by the time I had figured out that the fuse had blown the bar would be at full lock. Ultimately, I could not find the two wires that were shorting without taking the entire wire loom apart, so I simply immobilized the entire loom with a zip tie. The tester showed that the short was no longer occurring. Been working fine for a month. | ||
| Diablobrian |
I also saw a stripper in the Phillipines with intermittent shorts.........  | ||
| Gentleman_jon |
Was her name "Maxine" by any chance?  | ||
| Davo |
I had the same thing happen to me twice. I have been through the harness from tip to tail and found nothing. I re-taped and isolated high risk areas and it has not happened again in several months. I am now experiencing a bad miss during wet conditions. I have a fair weather adventure bike! I am afraid to leave town without tools, a cell phone, a box of fuses, a spare relay and a trailer on call. Confidence is fading fast! | ||
| Toona |
Jon, my XBS would do the same thing, blow the IGN fuse on full left turn lock. I found a wire that the insulation rubbed thru right above the horn bracket. I went thru 9 fuses last Sat. and 2 more tonight until I found my problem. IIRC, it was a red wire, don't remember if it had a tracer or not. The connector had 4 wires in/out of it. Hope this helps, BTW my bike is an '04 S w/ 7000 miles. I thought I may have had a shorting problem back at the fuse box, but everything checked out OK back there. If you need me to post a picture, I can. Previously, it seemed that when I sat on the bike it would blow the fuse, then I realised when I sat on it, the handle bars would "flop" to the full lock left. It just took a little longer to put 2 and 2 together. | ||
| Ride365 |
Toona you deserve some kinda Einstein award for putting that 2 and 2 together, Big Props! CHEERS!  | ||
| Roc |
I have been told to look for a short in the dark and also with a fine misting water bottle - have not tried either yet. | ||
| Gentleman_jon |
Dave, Perhaps your wet weather problem is a defective front spark plug wire, at least that was what the problem was on my '03 nine. Buell has upgraded the sparkplug wire, but left the parts number the same. Give Daves a call, he will send you the right one. Changing the wires out is a bit of a job, so if you are going to do it, you might just as well do both of the cylinders at the same time. Dan, Thanks for the tip. I do seem to remember that short being mentioned before. I will take another look. | ||
| Lovematt |
I also had the wet weather problem due to a front plug wire rubbing through. The stock wire was rather small with not much protection at the ends. The new wires have 'fins' on the ends providing much better protection. Had the problem at about 8000 miles and since then no problems at all and the wires are holding up great. | ||
| Slaughter |
I love that gadget. I keep a multimeter in the tool box but it means you have to use 2 hands, look at the display and still monkey around with the problem. You ought to be careful if you're by-passing a fuse (I'd add an in-line fuse holder to your rig "just in case" - available for about $3 from an autoparts store) If you keep power on to a circuit that normally blows a fuse, you can have a meltdown when the wires heat up. (I am soooooo tempted to play with the "intermittent shorts comment but most of you all beat me to it!) (Message edited by slaughter on July 08, 2006) | ||
| Gentleman_jon |
Slaughter The beauty part of this rig is that the filament in the bulb gets hot, absorbs the current, wires stay cool. At least that's the way I think it works. Perhaps some EE with a more than passing familiarity with Ohms law could elucidate. Anyway, once the light glows brightly, I just turn the key off. No smoke so far | ||
| Slaughter |
Jon - I'm also mystified by electrical stuff. I always refer to folks who work with ANYTHING electrical as "sorcerers and conjurers" If I can't see it bend, break, drip or squirt, it's a mystery to me. | ||
| Darthane |
Gentleman's right...the bulb is supplying resistance and thus keeping the current down. Type 1 shorts, which are typically what occur, place a short to ground before the load and thus have little to no resistance - which is what allows an excessive amount of current to flow and blow the fuse. Using a bulb in place of a fuse ensures that there is still a resistance inline with the circuit, so he should be fine with that rig (especially since it isn't permanent). The reason it glows brightly or dimly is because whatever component is downstream of that fuse is supplying an additional resistance when the short isn't present and thus dimming the bulb. The short gives it a direct line to ground and you get a nice happy 12V at the bulb for bright light. Rather ingenious little contraption, and one I wouldn't have thought of in a million years despite spending a good portion of my time troubleshooting vehicles. LOL (Message edited by darthane on July 10, 2006) | ||
| Slaughter |
Darthane, Way cool explanation. My paranoia comes from ignorance. | ||
| Darthane |
LOL...I'm often paranoid even where I'm not ignorant when it comes to electronics. It's rather odd, considering all electricity follows very basic rules (which makes it SEEM like troubleshooting them would likewise be simple), but I've seen even the best E/Es get stymied by some of the bizarre stuff that happens on a vehicle when there's an odd electrical problem. We had a vehicle built in Japan while I was over there come across the pond, and during transit suddenly the entire car decided to go haywire. When you turned on the turn signals, everything in the vehicle would dim and/or turn on and off in time with the flashers. Eventually we discovered a very long and convoluted sneak path, occuring because someone forgot to scrub the paint off of a ground attachment point, that wound it's way through the multifunction switch. It happened to include the run/start relay as well as a few other relay coils in the underhood PDB, soooo...clickclick...clickclick...clickclick... | ||
| Jaimec |
I'm going to Bermuda for vacation. Do they sell Intermittent Shorts there? | ||
| Darthane |
They only come packaged with sandals, black calf socks and Hawaiian shirts. | ||
| Jaimec |
You say that like it's a BAD thing! | ||
| Darthane |
I'm curious as to how you glean inflection/tone from a text statement on a message board. | ||
| Court |
>>>>I'm curious as to how you glean inflection/tone from a text statement on a message board. Like when the Russians said Leika (the dog they shot into space) looked "nervous" or "concerned". | ||
| Coastie |
I’m an electronic tech, and this tip has me a bit puzzled. Fuses blow when their current rating is exceeded. I could see this working with a very heavy duty bulb, but any other bulb would just burn out from the extreme current of a short, and possibly shatter throwing glass into nearby personnel. | ||
| Gentleman_jon |
Good point Jeff. That kind of accident could easily occur if one employed an under size bulb like a flash light bulb. In this case, the bulb was a 12 volt bulb from an old tail light of my Jeep. In other words, it was capable of absorbing all the current in an automotive or motorcycle circuit on a continuous basis. I should have mentioned that previously. Thanks. | ||
| Darthane |
Current is dictated by the resistance of the circuit and its relationship to the voltage. Less resistance = higher current. A Type 1 short is a short circuit BEFORE the load (most common, and the only type possible with many electronic devices), which result in little to no resistance in the circuit to ground and thus an overcurrent condition. Just for reference, a Type 2 short is a short across the load - most often occurring in solenoids and motors. Usually this does not result in as high a current condition as a Type 1, because there is still a resistance present in the circuit, but it often draws the current continuously, eventually overheating the circuit and causing a failure (blown fuse or melted component). You could put a 12V light bulb inline with a battery cable and run only that one bulb and it wouldn't hurt it, even if the bulb itself only drew 0.5A. Just because a battery is CAPABLE of outputting 100A doesn't mean it always outputs 100A. As he noted, if he'd used a flashlight battery (which are typically 3V-6V), that would cause a problem. | ||
| Slaughter |
They only come packaged with sandals, black calf socks and Hawaiian shirts. Hey, let's not be a HATER here! You got sumpin against calf sock tan lines? | ||
| Darthane |
I'll tell you the same thing I told Jaimec: How, precisely, do you infer that I was 'hating' or in some way opposed to sandals, calf socks, and Hawaiian shirts when the only punctuation involved in the statement was a period and there are no emoticons attached? ...my girlfriend regularly yells at me for being a fashion nightmare, if that helps you understand my frame of mind a bit more. | ||
| Slaughter |
Heck, I rarely go out without long pants and long sleeves and I live in the desert! You shoulda seen my skinny legs poking out from under my intermittent shorts last week on vacation! I saw grown men frown, women hide their eyes and small children cry! (Message edited by slaughter on July 12, 2006) |
