blown fuse

[bigbill]

I turned my headlight off as I approached the gate guards showed my ID put my glove back on started to drive away turned the headlight back on and then the bike went dead. The 15 amp fuse second one up from the bottom was blown. Installed a new fuse and zap. I dismantled the left controller with the head light switch and found a very small piece of silver solder and the white w/red stripe wire not making contact. I complete removed both the high beam and headlight switches and found some corrosion. One of the switches the plastic is cracked. I also noticed a couple of nicks in some wires. I left it all apart hoping that what ever caused the short although not fixed was at least not grounding tried another fuse and zap. Should this fuse have power even with the ignition switch off? The fuse blows with the ignition switch on or off. Does this mean the short is between the fuse and the ignition switch? What should I do next?

[BassCliff]

Greetings and Salutations!

Hi Mr. bigbill,

I'm sorry, I don't know what bike we're talking about, so I can only give you a couple of general suggestions. I usually recommend checking and cleaning every electrical connection and ground on the entire wiring harness, ignition switch, fuse box, etc. You've got a short somewhere. If you stop by my little BikeCliff website, you may find a manual for your bike that has a wiring diagram. Please click here for your mega-welcome, chock full of suggestions and links to vendors and other information. Thanks for joining us. Keep us informed.


Thank you for your indulgence,

BassCliff

[Steve]

I will second the plea to enter your bike information. We are presuming it's a GS or you wouldn't be on this site, but please help us help you by narrowing it down a bit.

One item is connected in the electrical system regardless of ignition switch position, it is your rectifier/regulator, usually abbreviated r/r or R/R. It is not uncommon for them to blow. Sometimes they just open up and don't regulate your voltage, sometimes they short out, which is what might have happened to your bike. A voltmeter will soon becoming your best friend.

.

[SqDancerLynn1]

The fact that you were turning the headlight on I would vote for the voltage regulator. Disconnect the red (BATTERY) wire and install a new fuse see what happends

[duaneage]

Sounds like something substantial grounded itself against the handlebars. Buy a bunch of fuses, they're cheap, and troubleshoot by wiggling wires.

[Steve]

Buy a bunch of fuses, they're cheap, and troubleshoot by wiggling wires.

Duane, I am sure your tongue was firmly in your cheek there, but I want to know your source of fuses.

Tain't so cheap here.

.

[duaneage]

Most are 10 or 15 amp, if 7.99 a pack for 5 of them is too rich I don't know what to say. Junk Yards have plenty and you can visually see if they are blown or not.
Improvise, adapt, overcome.

[76FJ55]

I am guessing it is your R/R. I am assuming Pre 80 if you have a headlight you can turn off, of course post 80 had the same switch but with a tab on the lever to limit its travel so yours could have beem modified. If yours is wired like mine, for some reason Suzuki decided to run the headlight off one leg of the charging system. I would have to go back and refresh myself on the exact details but as I recall it is something like this. the problem here is that when you turn the headlight off it eliminates the ground path for one leg of the 3 phase generated by the stator this causes excess heat build up in the stator and can cause stator failure. it also simultaneoustly forces the regulator to limit a lot of excess current since it can not be disipated through the headlight this can overload the regulator...

I am guessing that part of the diode pack in the rectifier section has shorted. this short will be present even without the key being on.

I would try disconnecting the R/R and then installing a new fuse. I beleive this will solve the fuse issue. of course then you will have a charging issue (which i'm guessing you have now as well it is just masked by the fuse issue).

I also suggest the this extra loop in the head light circuit be eliminated to help avoid this failure mode in the future.

[bigbill]

blown fuse

Sorry everyone it is a 81 GS750. The switch did have a cover to prevent it from being turned off. I have turned it off many times (coming onto base) without any problems before.

[Steve]

... for some reason Suzuki decided to run the headlight off one leg of the charging system. ...

Need to clear up a mis-conception here.

The headlight does NOT run off one leg of the charging system.

Yes, there are wires running from one leg of the stator up to the headlight switch, but they do NOT connect to the headlight circuit. Inside the headlight switch are TWO sets of contacts. One of them is for the stator wire. When the switch is turned ON, it allows the third leg of the stator to carry current. The second set of contacts will allow current from the headlight fuse to go to the dimmer switch, which then selects high- or low-beam. The wire from the stator goes back down to the r/r, then to the ignition switch, then back to the fuse box, then to the headlight.

The purpose of this was to limit the amount of excess current that had to be regulated when the headlight was turned off. For the first couple of years after U.S. regulations required headlights to be ON at all times, Suzuki blocked off the switch in the left control housing and simply looped the stator wire back to the r/r at a plug under the tank. For markets where the bike was sold that did not require constant headlight use, it was a simple matter to just change the harness that went to the left handgrip, instead of the whole main harness.

.

[bigbill]

blown fuse

Steve,

Where would you suggest I start?
Thanks
Bill

[duaneage]

The headlight switch probably shorted against the handlebar.

You detailed there were broken parts, loose wires and what appeared to be bad connections. All of this needs to be repaired and the best way to do that would be to try another left hand control.

Go to www.alpha-sports.com and get a part number from their micro-fiche they have on line. Find another bike (or two) with the same controls. usually the same size or close cousins used the same controls for a year or 3.
Once you know all the models and years that work go on a search through ebay or even the GSR parts wanted section and get another control. You should be able to get one pretty cheap, depending on the bike. 550 parts tend to be very easy to find.

[bigbill]

blown main fuse

Okay so it has been awhile since I last started this post. Finally got some warm weather and time to work on the bike. I replaced the left control pod. Fuse still blows. I un plugged one of the red leads from the rectifier and the fuse did not blow. So is it a given that it is the rectifier or should I keep looking.

[duaneage]

I've seen a shorted Regulator in an Suzuki RR. Looks to be a similar problem.

[Billy Ricks]

On my 700 if you follow the wiring diagram closely you will see the R/R goes to the ignition switch and back to the fuse box with no fuse in between. Once the hot wire leaves the R/R it branches off. One branch is fused, 15 amps, and heads to the battery. The other is unfused through the ignition switch and back to the fuse box where it branches off to each of the three 10 amp fuses. The one that heads to the ignition switch goes into it red and comes back to the fuse box orange. Check the red wire, it's the only wire that could short with the ignition off.