Blowing Main and Accessory fuses

[aerojack]

Hi!
New guy here, but not new to GSs. Started with a new '78 GS750, sold after having my first child ('83, wifely ultimatum), got a lightly used '79 GS1000 when kids started high school in '98 (the deal was get a bike once they were out of the house, but I figured it was getting close enough). Been riding that one since, but recently started having the main and accessory fuses blow when the revs go up. With good fuses, it will start and run around the neighborhood fine, once the revs go up the main and accessory fuses blow and after momentarily dying and then restarting from the motion, it continues to run fine but I have no blinkers, horn, gear light etc. Headlights work and it will stop and restart on the starter. Is this a dying regulator? I haven't checked the voltages yet.

Thanks for any help!

Jack

[posplayr]

Hi!
New guy here, but not new to GSs. Started with a new '78 GS750, sold after having my first child ('83, wifely ultimatum), got a lightly used '79 GS1000 when kids started high school in '98 (the deal was get a bike once they were out of the house, but I figured it was getting close enough). Been riding that one since, but recently started having the main and accessory fuses blow when the revs go up. With good fuses, it will start and run around the neighborhood fine, once the revs go up the main and accessory fuses blow and after momentarily dying and then restarting from the motion, it continues to run fine but I have no blinkers, horn, gear light etc. Headlights work and it will stop and restart on the starter. Is this a dying regulator? I haven't checked the voltages yet.

Thanks for any help!

Jack

Welcome aboard; it sounds like a short.

I would check the connections to the R/R especially the ground wires in the harness to see if one might have melted and is now shorting to a hot wire. You may need to open up the harness near where the R/R connects to look for where the red (+) and the ground B/W come to common points inside the harness.

[Redman]

Hi!
New guy here, but not new to GSs. Started with a new '78 GS750, sold after having my first child ('83, wifely ultimatum), got a lightly used '79 GS1000 when kids started high school in '98 (the deal was get a bike once they were out of the house, but I figured it was getting close enough). Been riding that one since, but recently started having the main and accessory fuses blow when the revs go up. With good fuses, it will start and run around the neighborhood fine, once the revs go up the main and accessory fuses blow and after momentarily dying and then restarting from the motion, it continues to run fine but I have no blinkers, horn, gear light etc. Headlights work and it will stop and restart on the starter. Is this a dying regulator? I haven't checked the voltages yet.

Thanks for any help!

Jack

Hello Jack, and welcome to GSR.

No, I dont think it sounds like a faulty R/R. But if you wanted to test your thereory you could unplug it (the red wire is its output wire).

I find it intersting that it blows the main AND the accessory fuse. Do you know what has been wired into the accessory fuse? Maybe as some trouble shooting try pulling the accessory fuse.
BY "accessory" fuse, I think that means the one on the bottom of the fuse box that powers the accessory terminal where can wire in things the owner mgih add like some extra lights or radio or some add-on accessory (or at least that what I think from my expereince with 850G and 1100G). ... please dissregard if 750 are different.

Or by "acessory" do you mean the horn-signal-instrument circuit?
If so, you could suspect the horn(s). I have heard of them blowing fuses intermittnetly like you described. Keep in mind that power goes directly to the horn all the time and the horn button completes the ground. So if horn has an internal short to ground it will blow fuse without having to push the button.
Seems that you are blowing fuses often enough that you could try disconnecting the horn and see if it still happens.

Is the main fuse 15 amp and the other fuses 10 amp?
But a short to ground could blow both at same time.

Jack , I would suggest that you add your general location to user profile and add your bike year/model to signature line (goto User CP). THen those both show up in every posting.

Dave
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