2013 Stelvio NTX blows headlight fuse

[Kuni0]

Hello everyone, it's seems that I'm here yet again for my yearly forum ask for something I can't troubleshoot on my 2013 Stelvio NTX. 

The problem I'm having this time is that whenever I turn on the ignition, the 10A fuse in the block near the steering head pops. 

I first noticed the issue several weeks ago when I started the bike and realized the headlights (and Aux lights) weren't working anymore. I replaced the fuse and it worked for about 2 min before popping again. Since then I've been down the rabbit hole. 

1. I thought it might be 'startus interuptus' coming to finally get me even though I had fused the Aux lights some time ago. But checking the main (30A?) fuses on the right side panel showed them to be good.

2. I disconnected the headlights and Aux lights and it still pops the fuses every time I turn on the ignition. 

3. Got new relays and replaced the ones for starting and lights logic (2x of the special 4 pin)

4. I got the guzzidiag on it, read the error codes and found a P0170 error (no electrical signal). I traced the wires from the ignition to a connector on forward, right side of the bike near the ABS control unit. I cleaned it with some contact cleaner, put some di-electric grease on it (and the other connects in that area) and fitted the tank on just enough to get the engine running. That seemed to have done the trick with the headlights and Aux lights working and the battery charging. But as soon as I properly remounted the gas tank (tightened it down) it continues to pop fuses again every time I turn on the ignition. 

5. Took off and on the starter motor, checking the grounds underneath it. No change. 

At this point I'm out of ideas. My instinct tells me that there's likely some ground connection with the ignition that isn't working properly, whether that's with the connector underneath the tank or some other ground wire I haven't identified. If you have some ideas or advice, I'd greatly appreciate it. 

Thanks in advance

[audiomick]

Hi Kuni0,

my guess is that the fuse is doing exactly what it is designed to do, and you've got a short circuit somewhere. Not a bad ground, much more likely a wire that carries 12V with damaged insulation, or something like that.

This

2 hours ago, Kuni0 said:

...But as soon as I properly remounted the gas tank (tightened it down) it continues to pop fuses again every time I turn on the ignition. 

...

indicates strongly that the problem is under the tank. Start looking there, and you're looking for a spot where the tank sits on or rubs against the wiring loom, quite likely where the loom is pinched between the tank and the frame.

Edited September 2 by audiomick

[gstallons]

Print off a (large) wiring diagram for your bike. See what circuits this fuse serves and then follow the wires AFA where they go on your bike and look for a pinched harness or wires. Look specifically for the area under the tank. 

[Kuni0]

I am back with an update, in which is this no change. 

At this point the tank is off (so theoretically no pressure/ pressing on wires) and it still continues to pop the 10A fuse. The issue definitely seems to stem from the connectors underneath the tank near the ABS control unit, but I'll be damned if I know the correct combination to make it work. I did get close where it didn't seem to be popping fuses with the tank on (not bolted in) and was able to turn on the bike with working headlights. But as soon as I bolted it in and went to start the bike the fuse popped (though the ignition was able to turn on without popping) 

It is a good suggestion to try and trace the wires connecting from the wiring diagram to the bike, and I have done that, but all the wires are bundled up into the harness and I'm not keen on cutting into the wiring harness 

[Kuni0]

Here's what I'm looking at. The lines with the blue electric tape I've marked as connecting directly to the ignition. I've tried to make that bundle of wires as slack as possible, and it still pops fuses in this state. The connectors look fine as well (no obvious damage)

[gstallons]

As for now , we know nothing more than you.

 And I'm not being a smartass.

Edited September 9 by gstallons
more info

[Pressureangle]

You have a short circuit. Simple As. 

I used to tell my students, 'You can find 99% of faults with your eyes and fingers'.
It's very unlikely that the short is inside the wiring harness where you can't see it. 
Here's how I'd approach it. First, eyeball and finger every place where the harness lays against the frame. This may require cutting zipties and disconnecting connectors. 
If it doesn't present that easily, use the wiggle test. Connect a test light clip to your positive battery terminal, and the point of the test light to the user side of the fuse connection. (fuse out of course) Disconnect the users, if I understand correctly the headlamps. Turning the switch off, if Euro where it completely disconnects them is ok.
If the test lamp is lit, wiggle all the harnesses until you find a place that extinguishes the lamp. If the lamp is off wiggle everything until it illuminates. That places you pretty near the problem. Then eyes and fingers. Anything more complicated than a rub-through is going to take a proper wiring schematic. ;
 

Edit; all of these tests with ignition key off.

Edited September 9 by Pressureangle

[Kuni0]

Re-reading my message, the tone was a lot more aggressive than I intended (my personal frustration seeping through) and I want to apologize, especially to those trying to help me. 

Next steps I'll re-read with the Guzzidag and see if there are any new, noteworthy codes, and start cutting at some zip ties to try and see if the short still presents itself. I'll also order more fuses and the light tester in the meantime

[Pressureangle]

I've never had my eyes on a Stelvio, but don't forget the harness runs all the way to the headlamps. Back in steel-bucket lamps, a worn through wire in the nest of snakes inside the bucket was common.

[audiomick]

14 hours ago, Kuni0 said:

...The lines with the blue electric tape ...

That's the first place I'd look. Luigi doesn't use electrical tape. Someone has been buggerising around in there. Take off the tape, and see what is inside.

 

Apart from possible defects in there, leaving electrical tape on for more than a couple of weeks is not good. The adhesive deteriorates, and you are left with peeling off tape and a smeary, sticky mess underneath. 

[Pressureangle]

6 minutes ago, audiomick said:

That's the first place I'd look. Luigi doesn't use electrical tape. Someone has been buggerising around in there. Take off the tape, and see what is inside.

 

Apart from possible defects in there, leaving electrical tape on for more than a couple of weeks is not good. The adhesive deteriorates, and you are left with peeling off tape and a smeary, sticky mess underneath. 

Ah, you did not put that tape there yourself? If not, certainly get it off to find the Cracker Jack prize underneath. 

[Speedfrog]

9 minutes ago, Pressureangle said:

find the Cracker Jack prize

Man, you are full of (sur)prizes, first Good & Plenty and now Cracker Jack . . .  

[Pressureangle]

40 minutes ago, Speedfrog said:

Man, you are full of (sur)prizes, first Good & Plenty and now Cracker Jack . . .  

I haven't begun to Bit-O-Honey or Necco wafers yet.

[gstallons]

Does your bike have a wiring diagram or can you locate a wiring diagram ? You do need to decide which fuse is blowing and what it services. Then go and research what is causing the problem area. A box of fuses and start looking! Good luck.

[gstallons]

When you get proficient w/wiring diagrams , you will not try to do anything w/o one.