Help with V85tt

[k98shooter]

Dear Guzzi experts! I am trying to bring back to life V85tt after crash. The impact was on the front end. The issue I am having is that the bike keeps blowing main 30 amp fuse as I connect the battery. With dead bike and blown fuse, the rectifier is buzzing continuously (battery connected, of coarse…). Initially I thought it was a short in the fuel pump relay, but the buzzing kept on with the relay disconnected. And I can feel it is indeed rexrifier. Is it likely that if damaged as a result of impact, it is causing all these electrical troubles? Thanks a lot!

[guzzisteve]

It could also be a shorted stator. Was the front cover on motor impacted w/damage? Pinched charging wires? More info needed.

[k98shooter]

Yes, the front cover has a dent from the impact, right where the eagle relief is.

[guzzisteve]

I would change the regulator but have the stator/alternator fully checked before installing regulator. Make sure cover doesn't leak oil. If changing the cover it's all right there to check. The fuse goes to regulator and to one side of fuse panel.

[k98shooter]

Disconnected the voltage regulator. There is no main fuse, buzzing remains. Please see the short clip below. Front cover appears intact, What I thought was a dent, is an eagle relief.

https://youtube.com/shorts/iBVonvmXi6s?feature=shared

[michaell32]

Sounds like a weak horn that is stuck on.

[Huzo]

Sounds like a weak horn that is stuck on.

Actually it does…

[guzzisteve]

I would think that you could feel vibrations and noise w/your touch if you can't w/your ear. Just an idea.

[k98shooter]

I couldn’t feel vibration, but it appeared to be the source somewhere behind the timing cover, but I am not sure. Here is more: After I disconnected voltage regulator and put new main fuse, it stayed intact, and it blew once I plugged the regulator back. Ordered new regulator, will update if that solves the issuy.

[guzzisteve]

I couldn’t feel vibration, but it appeared to be the source somewhere behind the timing cover, but I am not sure. Here is more: After I disconnected voltage regulator and put new main fuse, it stayed intact, and it blew once I plugged the regulator back. Ordered new regulator, will update if that solves the issuy.

It blew & quit blowing noise? Much cheaper fix than stator. I don't see how the alt could be making a horn sound but who knows(not me).
Now you can do a alt test for ohm's if that's in the book, otherwise start it up & check AC voltage. It will run on a charged battery w/o regulator. I think, don't know I don't own anything new. They came out after I retired from the MG shops.

[lcjohnny]

Have you removed the damaged casing and checked what happens??

[k98shooter]

 No, the timing cover  is intact. What I thought was dent, turned out recessed eagle logo. I want to see if new voltage regulator solves the issue

[k98shooter]

Just wanted to post an update. The humming sound is coming from ABS control unit. The sound goes away after ABS unit disconnected. (Disconnecting 20 amp fuse next to main fuse does the same effect). But I am not sure how this is related my main trouble. 30 amp fuse keeps blowing if voltage regulator DC output is plugged in (black plug with two black and two red/white wires, circled on the diagram). I swapped voltage regulators, nothing changes. So VR can be excluded as a culprit. The main fuse keeps blowing when all other fuses are disconnected, i.e. there should be no offending load. This leads me to think there is short somewhere along DC feed to the battery. After removing the tank I can’t see any visible damage or any bare or pinched wires. Not sure where else to look from this point.

[guzzimaster]

 :thewife:I hate to admit this, but I experienced a similar noise and fuse outage when I discovered I connected the battery terminals incorrectly!   

[Motormike]

Best of luck.  I learned the hard way about hidden crash damage trying to repair a Harley Davidson after a crash.  Won't ever go down that bottomless rabbit hole again.  I take the insurance check and RUN!

[Littlefield]

Don’t know if you got this resolved. Since the problem started after a front end crash I wonder if wheel speed pickup is damaged or out of alignment.

[k98shooter]

Problem resolved and it was indeed voltage regulator. Thank you all for help!

[Tkelly]

How did you figure it out,your Dec14 post indicates Voltage regulator was not the problem?