Tach issue

Cruised the boat today. Beautiful day in South Texas!

After about 1.5 hours of cruising my tach RPM started showing low-- like 900 rpm when I was probably doing around 2000.

I also got a high voltage error code on my Balmar Smartguage. Underway at RPM it was showing like 14.7 volts. Back at the dock I put the multimeter on it and at idle it was 14.5 volts.

Is that too high? It's a Balmar alternator. Would that high output have anything to do with the tach? Wires are tight at the tach and on the alternator.

Thanks!

pulling up a chair and getting ready to learn. Seems smarter than giving you the answer I think is right which will be proven only partly right 3 posts later

What model regulator? Balmar Manuals

Page 9

Damn I forgot to get the model number when I was down around the battery box. It's a Balmar duo charge. Regulator.

It is set for AGM batteries. I have a new set of AGM batteries for the house bank and don't want to screw them up.

Balmar alternator/regulators will often peak at 14.5 or so, just before switching from acceptance to float. You need that much voltage to drive the amperage into the batteries.


But who knows if you were at that point on the charging algorithm. Some, maybe all Balmar alternator's give you an LED readout that tells you which charging mode: bulk, acceptance, float that you are in at the time you look.


Why the tach was reading low is anyone's guess- bad connection, maybe. Is it connected through the Balmar regulator? That regulator has a frequency divider to match the alternator's pulses to what the tachometer is expecting. But it should be constant.


David

Thanks. I will do some more research and testing when I get back to the boat.

Which engine do you have and year?
Do you know where the tach signal is taken from?
Some engines use the alternator to provide the tach with a signal, some engines use a flywheel sensor, some older ones use a separate voltage generator.

Some tachs pick up a signal from the alt.

As the voltage rises to the point where float cuts in , perhaps there is too little voltage for the tach to count pulses.

This can be solved IF the engine has a place for a mechanical driven set of points for the tack, it will also make the tach accurate , the alts driven ones seldom are .

C lectric said:

Which engine do you have and year?
Do you know where the tach signal is taken from?
Some engines use the alternator to provide the tach with a signal, some engines use a flywheel sensor, some older ones use a separate voltage generator.

Click to expand...

It's a 2008 Yanmar 4Jh4-hte. I figured the alternator supplied the tach signal but could be wrong. All wires seemed to be tight on alternator. Voltage at pos and neg on the alternator itself was 14.5 at idle.

Maybe the alternator is fine and my little Balmar Smartguage is just acting up. Need to investigate the 03 high voltage error code.

Can I fry my AGMs with 14.5-14.7v?

I have a Balmar alternator and their ARS 5 regulator.
I also get strange activity on my tach and it's very repeatable.
Only happens when I leave the dock after being on the shore charger .
After approximately 1 hour my tach flutters a couple of times and drops to 0 rpm.
It will stay at 0 for approx. 3 minutes, then it flutters a few more times and comes back to the previous and correct rpm.
I say repeatable because I often go to the same anchorage from the marina and this happens at close to the same place every trip. (no not the Bermuda triangle).

If I run the boat after being on anchor and depleting the batteries this does not happen.

I am thinking it may be after the 2 initial 36 minute cycles so maybe it's 72 minutes, I will have to use a stopwatch to know exactly. Someone suggested that the regulator stops charging to check battery voltage so maybe that's why I lose tach signal.

Balmar suggested I start playing around with voltage settings, but everything else works so well I hate to monkey around too much.

Not trying to steal this thread, but thinking our issues may have a common cause.

Greetings,
Mr. j. I encounter exactly the same symptoms with my Balmar system and have come to the same conclusions (regulator stops charging). I'm not going to fiddle with it either.

Hmmm. That sounds similar to mine. It always seems to happen about the same time on my little loop cruise I do-- after about two hours or so.

And this is after mine has been on shore power and the charger.

I am scared to "play around" with the regulator. It takes some kind of special tool and I'm sure I would screw it up somehow.

With your draft some of the south bay rivers are open to you. I suggest getting a good chart and comparing it to a local map. I think you will find it possible to go up river a bit and get closer to some towns and attractions.


beaching on one of the many small islands was fun back when I lived there. Set up camp and have the island to yourself. Clams were readily available in shallow water back them as well.


Watch hill park and marina is still a popular spot on the east end of Fire Island. Don't pass up Peconic bay.

Don't know if this is related to my tach issue or not, but yesterday the tach refused to work again, and now the autopilot/plotter has started acting crazy.

About an hour into the trip the plotter actually spun 90 degrees and showed my boat going sideways. It then spun 360 degrees, like it was hunting for a heading. It could not figure out which way was up basically.

I tried turning it off and restarting it but that didn't work.

I tried to engage the autopilot and it immediately turned the boat about 90 degrees or so.

??

Are you cruising near Area 51

I had that happen on a seacat at about 30kts... nearly threw me off the boat!

If you fire up the AP, let it get a bearing before you engage it. In my case, it used the last known bearing (going home) which was 180 off where we were going.

Can you check voltage at that helm...maybe @ the plotter supply. Does the plotter have a separate breaker or if it is with something else is it affected? What is the Amp or Volt meter saying when this is going on? Have you changed anything else prior to this challenge? Bunch of questions but it is time to start eliminating the gremlins.

Can't think of anything I have changed. I will check the voltage. Ground.

Could something be interfering with the autopilot maybe?

Back at the boat today. Tach was not working when I started the engine. Accessed alternator, unplugged connector and plugged back in. Checked all other connections-- all seemed tight.

Restarted engine and tach working. Bad connection at connector maybe?

Found flux compass for autopilot. There were some bungee cords thrown on top of it when cleaning last time and they have metal on the ends. Maybe that's it. Too rough today to go out and try AP today. Will try later in the week.

Garmin plotter question: sitting at the dock should my GPS heading be way off from mag compass heading? Plotter says 2 degrees true and compass is at about 210. Does the boat need to be underway for the heading to be accurate? I've never noticed the difference at the dock I guess.

I would put a new connector on the tach wire that way you'd be sure. And if its a pull off type, make sure it fits tight. Squeeze the female end if necessary (RT I know you'll comment on this LOL).

Greetings,
Mr. jl. Nope, good advice...Carry on.

Just to eliminate one gremlin...run a secondary good ground.

bilge53 said:

Just to eliminate one gremlin...run a secondary good ground.

Click to expand...

From the tach?

The tach and the cluster. Bad grounds do weird things.

Ok. Thanks.

bilge53 said:

The tach and the cluster. Bad grounds do weird things.

Click to expand...

Great advice!

cardude01 said:

Don't know if this is related to my tach issue or not, but yesterday the tach refused to work again, and now the autopilot/plotter has started acting crazy.

About an hour into the trip the plotter actually spun 90 degrees and showed my boat going sideways. It then spun 360 degrees, like it was hunting for a heading. It could not figure out which way was up basically.

I tried turning it off and restarting it but that didn't work.

I tried to engage the autopilot and it immediately turned the boat about 90 degrees or so.

??

Click to expand...

If you suspect that your autopilot is getting interference, you can check any power cables that are located near it for interference. There is an Ap that you can download for free to an android phone (i'm sure there is something similar for the I-phones as well). It is called a gauss meter. I have one on my phone that I use in cases like this. I don't know if it is related to the Tach issue, but I would suspect not. Probably 2 different gremlins. sometimes just moving a power cable closer to the autopilot cables can cause the issue.

seadogmike said:

If you suspect that your autopilot is getting interference, you can check any power cables that are located near it for interference. There is an Ap that you can download for free to an android phone (i'm sure there is something similar for the I-phones as well). It is called a gauss meter. I have one on my phone that I use in cases like this. I don't know if it is related to the Tach issue, but I would suspect not. Probably 2 different gremlins. sometimes just moving a power cable closer to the autopilot cables can cause the issue.

Click to expand...

Interesting. I will see if I can find that app for the iPhone. I did find some bungees with metal ends that were thrown on top of the flux compass and removed those. Have not had a chance to go out and retest/recalibrate the AP.

When the AP started acting up I tried to do a recalibration by doing the slow circle thing with the "swing compass" on, but too many boats to contend with and too many people on board for me to concentrate, so I couldn't finish that.

Think I got the Tach issue, but like the suggestion for an additional ground for the tach.

bilge53 said:

The tach and the cluster. Bad grounds do weird things.

Click to expand...

Can I ground the tach and cluster to the big DC ground buss bar behind my DC panel? It's easy to get to.

Boat electronics are not my special area. Mental block. Scared I'm gonna blow something up.