Tachometer not reading correctly

[R.B.]

The tachometer on our boat does not sit at zero when the engine is turned off. And when you start the engine, it picks a random place to start reading (ie. 2000 or 3000 rpm). Once you rev up the engine a little it goes to the needle stop at the bottom. Only occasionally does it read correctly. Has anyone else experienced this and fixed this? I still am waiting for a resolution from the dealer, but I thought I would ask here to.

Thanks,
R.B.

[calgon]

Ours does the same thing. According to Turner Marine this has been a common problem. They shipped us a new one but I have not installed it yet. Ours works correctly about half the time.

[jfriers]

We have also experienced this problem. Our dealer has ordered a replacement. As soon as it is in i'll give an update if this fixes the problem.

Jim Frierson
S/V Let it Breeze
Hull #308

[william vanwagoner]

I have also had this problem with the tachometer, and just experienced my second tachometer failure. My first tach lasted about 6-months. First, it would bounce up and down between 0 and 1000 rpm, and then stay at 0 upon throttling up above 1000 rpm and stays dead. Interestingly, turing on the bildge blower sometimes brings the tachometer back to life to normal operation, but goes back to zero when the switch is turned off. It took about 6-moths to get a new tach, and has lasted for about ten months up to today, when it is now showing the same symptoms as the first tach, including the interesting behavior with the bildge blower.

How many folks have had this problem? Has anyone noticed the same thing with the bildge blower switch? Has anyone experienced multiple failures and has anyone found a solution? Is there just a bad batch of tachometers out there?

Thanks,

Bill VanWagoner, #229

[R.B.]

I received and installed the new tach on our boat and it has operated correctly up until now. Even when the batteries are full, the tach reads correctly. Unfortunately, lift out for us is in 3 weeks so, I will have to wait until next year to give it a good work out.

[Last Boat]

My tach began to act up this weekend. It would actually change up/down by about 300 RPMs with no movement on the throttle. While throttleing up, it would jump about 1500 RPMs over my estimate of the RPMs. I never had a good feeling that it was registering within 300 RPMs of my estimate. How difficult was it to obtain and replace the Seaward Control Panel?
Nelson Gainey
Last Boat
C350 #345

[R.B.]

Removing tthe tachometer from the panel was very straightforward. Remove the panel from the pedestal. Make a diagram of the wires and where they attach to the back of the tach first. Then remove the wires from the tach, unscrew the bracket holding the tachometer, and pull the tachometer out from the front of the panel. Replace with new one. I took a digital photo of mine before disassembly instead of drawing a diagram. So far my new tach has worked flawlessly. According to the dealer there was a bad batch of tachometers made and they were installed on various models of Catalinas. The dealer shipped me a new one within a number of weeks under warranty.

[Chris]

I think the problem is with your alternator not your tachometer. I replaceed my 53 amp alternator with a 105 amp unit. No problem. Need to upgrade the wire size from the tach to hande the increase in amps. Used #2 wire to ground and to the + post of the starter solenoid.

A 203 Catlina 350 had their alternator rebuilt. Mine is a 2004 #138.

I think there is a problem with the fctory wiring. I have had to replace 2 batteries so far. after disonnecting one battery I could not get power to the pedistal to start the engine and the tank guage would not work. After connecting both negative wires together all worked fine. Why would this happen??? Something is wrong!? I will trace wires next spring when I put it back in the water.

[hansgrasman]

Noticed history on tachometer. Replacing mine. Any suggestions on make and model ?

Appreciate your comments.

Thanks

[leigh weiss]

Hans
Has your unit failed?
Why do you want to replace the Tack?

Leigh Weiss Brisa #155

[hansgrasman]

Leigh
Sometimes when I start the engine the RPM reads 2500 or more when I know the engine is running at much lower rpm . The problem resolves itself when running for about 10 minutes.

Having various things checked this week. Such as the tamper plate. Windlass oil leak.
water tank sensors.

Plus my attitude of "do I really want a boat ?"

I was one of the early pioneers getting the kinks out of the engine noise and prop problems and after
everything was fixed by Catalina I made a promise to Mr. Frank Butler to stay of the C350
bulletin board. I kept my promise and I have been real happy with the boat. Now I have the regular aging problems
with my boat. my mind and body
Doing yoga 5 times a week just me and about 15 ladies . It seems to work. Lot less lines to pull.

Hope Mr. Butler is still doing well, being in his 80s and keeping customers happy. What a man !

[leigh weiss]

Hans,
I have found for the majority of the problems with the Tack is connectivity problems.
There is a rotary switch on the back of the tack that might need some exercise to clean the contacts (remember the start position to get back)
The ground and sense wires for the tack go to a terminal strip behind my dash. I have cleaned and tightened the screws and used electrical grease to cover the connections. Also look at the connections on the alternator make sure they are clean and tight.
I have also found tight connections with oxidation between the surfaces. As a general rule I remove and clean even the tight connections and apply protective electrical grease. This is only a once in a few year service.
Think of this as therapy and another boat bonding experience!
Let us know how you make out.

[reinhardschumann]

My tach has also been doing this for the last few years, reads too low at first then reads too high for a while, then reads correctly. When I knock on the glass it bounces to different readings. It's a 2008 with Universal M35B.

[Richard Ad]

Hello Reinhard; my 2005 was doing the same thing. Boat Tech guys tell me that poor conductivity is the cause 99% of the time. I cleaned my connections on the back of the tachometer and on the alternator and all seems good so far in 2020. Good luck.

[scott.monroe]

Hello Richard,
Leigh Weiss mentioned this in 2014 but the rotary switch on the back could help the problem. See the picture.

I had had the same issue sometime ago and had contacted the manufacture/catalina(?) who suggested simply rotating the switch back and forth which helps clean up the surfaces internal to the tachometer. The important thing they said is to note original position of the switch so that it gets back to the correct operation. Have had good operation since.

Good luck,
Scott

[bjtimm]

I bought a new tachometer to put in, saw this post, rotated the switch and voila! My old tach is working just fine! So glad I read this forum first.

[eTrial]

Hi All,
I have had a problem with my Tach operating correctly for about a minute then the needle falls to zero.
I thought it was the Tach so I ordered a replacement. Same issue with the replacement.
I searched and searched to see if anyone had a similar issue and ran across a post where a user reported a similar issue when his solar array had fully charged the batteries.
Next time I was at the boat, I repeated the behavior, then turned off the battery charger for a few minutes. Next time I started the motor the tach worked normally.
I suspect, but do not know, that the way the tach is wired to the alternator is the issue. The alternator will run for a brief time until it sees the batteries are fully charged then shuts down.
Hope this helps,
George
Life is Short #266