Front Brake Causes Gauges To Go Out

[happypunch]

Hey, folks!

 

A few days ago, I noticed whenever I used my front brake, the gauges would cut out. Everything, except for the speedometer (having just replaced that, I know it is cable driven or else it would have crapped out too, I'm sure!). Even the LED indicators like for the fuel and clock turn off. The second I release the brake, it all comes back to life. You can do it several times in a row until it just stays off and you have to turn off the key before it will work again.

 

This is crazy weird to me. I don't have any other electrical issues and my bike is just the base model so there's less to go wrong. I started following wires and making sure that connections were clean and tight and was keeping an eye out for any insulation that may have rubbed off and causing a short but haven't had any luck so far. I've even removed the front brake master cylinder from the handlebar to make sure that I wasn't just jiggling a loose connection in the starter switch and I can't replicate the problem when I fiddle with the starter switch, just the brake lever.

 

Any thoughts? I've tried digging through old posts and haven't seen this problem so I'm hoping someone can help point me in the right direction!

 

Thanks!

 

Forgot to say this is for my 84 xvz1200

[cowpuc]

I think if it were mine I would be looking closely at the brake light switch that is activacted by the brake lever itself. I would unplug it, stick an ohm meter on it and check it for continuity thru the switch and also check it to ground as you work the switch. I have had bulbs short out at a broken filment back feeding to ground too but if that were the case, it seems you would be seeing it when using the rear brake too..

Another possibility is if you or a PO swapped on MK2 forks are you are using the electric anti dives that come on that swap? If so, it might be possible your issue has something to do with a short that system..

Also check your battery connections and fuses (known issue) where they lay in the holders if your scoot has the OEM fuse box..

[Karaboo]

Check every single ground. Several times.

 

Sent from my LM-V405 using Tapatalk

[happypunch]

Well, I've struck out with the grounds. I'm not sure what would make the switch itself cause the issue since it should just make it be on or off, but the stupid switch doesn't even make the taillight come on, so it probably needs replacing anyway. I think my next step is to pull apart the fairing and thoroughly check each wire to find a short. 35 year old bike with 77k miles and I'm sure there's bound to be plenty of insulation that's rubbed a bit thin. In a perfect world, I would like to redo the harness, but that would take a ton of effort and $$.

 

Something that started at the same time is my front brake master cylinder developed a leak out the inspection window. I noticed when I first got the bike that someone had done a repair on the clutch inspection window by epoxying a dime in it. When that thing died, it went out in a blaze of glory. Of course I had picked my wife up for lunch and on the way back had a torrent of brake fluid dump out and the clutch wouldn't budge. Some time in a parking lot and some new fluid didn't help since the seals were pretty much dust. But I managed to get the 6 miles home by starting in neutral, revving a bit and stomping into 1st. Rev matching allowed for shifts on the way, but I had to try and time traffic lights perfectly... Luckily my transmission was fine. Tried to rebuild the master but it was so pitted that it barely worked so ended up getting a clutch master cylinder from an 04 fjr1300 and it works like a champ. All this rambling is heading somewhere. I promise!

 

So, since my brake master cylinder is also not working (shaved dime and jb weld fixed the inspection window leak but it's not building pressure) I'm looking into options to upgrade/fix that problem. Ive been reading up on folks using brake rotors from r1/r6 bikes and I'm sure that I can make a master cylinder and lever work no problem. This would be a great time to upgrade and what better master cylinder to use than the one that matches the calipers, right?

 

The concern I have is this: does it matter what year of r6 to use as a donor? Do they all bolt up the same? I read somewhere that the xvz1300 forks are the ones to use so it bolts up and I already have a set of those ready to go on. There's a guy near me selling a set of 03-09 r6 rotors, lines, master cylinder and lever and I really hope that will fit. Plus I will have a new brake switch and get to de-link my brakes at the same time.

 

What are your thoughts? Should I be looking for different years? Just get another fjr1300 master and worry about calipers later? Do I need specific brake rotors to go along with all of this? Any links to threads that I may have missed when searching the site would be appreciated!

 

Thanks, everyone!

[happypunch]

It's fixed.

 

I'm happy it's fixed but I'm unhappy because I don't understand why it's fixed. I went over the grounds with sandpaper and made sure all the connections were tight and that didn't seem to do anything. I figured I would give my old brake master cylinder one more shot and was pleasantly surprised to have it building pressure again. Bled the brakes and now the front brake is working (as well as the crappy stock brakes ever did) and now the dash doesn't shut off when squeezing the brake lever...

 

Like I said, I'm happy it's working again but super confused to what the problem actually was. Since I don't know exactly what caused the issue, I'm worried that I will be updating this thread in a few months saying the problem came back.