My No Tach issue reared it's head again on my trip last weekend... few hours or damp riding and next morning, I had no tach when we went for an early morning ride.. an hour of dry, warm wind plus road vibrations, and the next time I restarted the bike it came back to life. Same issue next day.

This has happened some two years ago after washing the bike, and a bit before that when i got caught in a Texas downpour (actually soaked through my riding pants and filled my riding boots)

I have never really figured out where the moisture is getting to,, inside the cluster, or a connector someplace.

Never find anything visible when i get it home and taken apart.. no corrosion, no dampness.. and I don't think it is a open wire,, as the issue only comes up after getting wet, and fixes itself.. Though It could be a wire missing insulation and grounding out when wet

IN any case..... wiring diagram in hand.... and off with the plastics... I'll trace every inch of the tach signal wire and see what I find...

Of note, nothing else shuts down or acts weird.. just the tach.

If you have an idea or a know issue Im not tracking, please, speak up.

 

I have had the same issue. My tach and ODO stopped working after a wash. I put Dielectric grease on the front and back of the plug that is on the back of cluster and have not had an issue since. Hope this helps

 

For sure dielectric on every connector whether corroded or not.

I lost my tach after drilling the subframe for my givi rack. Turns out, my usual practice of looking behind where I am drilling woulda saved me hitting the harness, which is BTW NOT drillproof.

Anyway, tach died to never return, so put on an aftermarket one. In the end turns out the black box in the tail was the problem so had to get a new one. That solved it.

 

Im reasonably sure it was moisture in a plug... and I think it was the two behind the cluster... But as it was working just fine when I took the bike apart tonight, who knows.

I found no moisture, plenty of silicone grease, no corrosion in any plug or inside the instrument cluster.

But all cleaned with electronic cleaner, dried, dabs of silicone grease re applied, and all put back together.
After the fiberglass resin dries and I get the lower fairing painted.. ..installed.. We will run her around town a few days and see what's up.

 

Good Luck, I wish I had more for you.