Bouncing tach

[Bandrews7]

My tach started bouncing this weekend. Reading way higher than it should. If I tapped the bezel it would go back to normal reading. Any ideas?

[Cobalt]

I have the same problem, and was told by the dealer the tach needed to be replaced.

Unfortunately, the tach is no longer in production, and I could not find a replacement.

I have been tapping the bezel once or twice for the last 5 years, and it is still working fine.

Good luck.

[Dave R]

That's a really common problem with Faria tachometers. Mine does it now and then, and my last boat with a Faria Tach did as well. Smacking it has always cured it in the 12 years I have seen it, so I've never looked for a permanent solution. If yours is not a Faria, it may have a similar design.

[salty dog]

Mine does the same and the old tap works fine, just like in my old Wellcraft before I finally had to replace it. I'll keep tapping until it's not working, if it comes to that, then I'll replace it.

[Rich]

If you do have a Faria, you may want to contact them. They can rebuild your current unit for a fee.

http://faria-instruments.com/site_manuals/IS0090L-9128.pdf
http://faria-instruments.com/forms/?form=new


Or just keep tapping! ;)

[Rinkerfam]

We had the same issue with our a few years back. I thought I was going to have to replace it. The mechanic at my marina said that he could remove it and send it to Faria for a rebuild. I paid for the cost of the rebuild plus shipping and it has been fine since. It's a worthwhile option in my opinion.

[pcmc]

Does rebuild it mean lubricate all moving parts??

[welchislandman]

I have the same issue in my 03 Rinker
I never tried smacking it ! But will now

Thanks for posting the rebuild link also

Jeff

[pcmc]

After thinking about mentioning lubricating any moving parts, the thought that everyone most likely has a much newer and nicer boat than mine, crossed my mind.
So curiosity won and I googled the tach and sure enough the tach works via pulses from a pickup on the engine vs a cable from the distributor. So to learn a little more I called Faria, which I was pleasantly surprised to learn they are based in CT.
I explained that on Winnipesaukee.com I had read about an issue some are having with a bouncing needle on their tachs. The gentlemen I spoke to offered this as a slim chance to correct your issue.
On the back of the tach is a button or switch that allows the tach to be adjustable ( universal )and work with different engines. First make note of this buttons position so you put it back in the same position. Move the button back and forth to try to 'scratch' any corrosion off that may have formed on the contact points. He did say as the tach begins to show signs of failing the needle will occasionally bounce and eventually get stuck in one spot and stop working. This was beyond a corrosion issue.
Start with trying to scratch/ clean the button by moving it and check that connections are tight and corrosion free.
I like tinkering with older cars and as wiring and connector metals oxidize or corrosion occurs is when funny electrical issues pop up.
Hope that helps.
Good luck.

[Rich]

Yes, I've seen this switch. It's on the back of the tach.

Rotate the switch several times, quickly. Then put it back in the correct position (4, 6 or 8 Cylinders).

It may help!

[ITD]

Check the ground, make sure it hasn't corroded.....

[Rich]

Check all the connections!

I happned to be behind my dash for a different reason, and while I was there I looked to see if any connections were loose (the boat is about 9 years old).

As I wasnn't having any symptoms, I couldn't believe what I found. One of the nuts behind the temperature guage was not even close to being tight, so the wire connector was just hanging on the guage lug loosly! The nut was about half way down the post. Luckily that guage was working perfectly, and never was a problem. But it was a problem waiting to occur.

While I was back there, I took the time to check and tighten all the connections.

So if you take the time to get behind your instraments, it wouldn't hurt to check every conection.

[VitaBene]

I have a non-operating Faria tach on my Wellcraft, thanks for the ideas!

[Rangervx]

there is nothing to lubricate to fix your tach...it is most likely a wiring issue...check and clean all connections before replacing the tach if it is still faulty...