The hours on my tach rarely show. Once in a while they come back for a moment then gone again. I have cleaned the electrical connectors but that does not seem to help. Any ideas? Maybe the sending unit?
Erratic tach
- Thread starter Sailgunner
- Start date
SG -
Our h36 has a Yanmar 3YM30 with a "new Type B" panel that uses pulses from the alternator stator to an OEM VDO tachometer and has a blank engine hour gauge as well. In fact, the two H36's we looked at ('07 and '08) at our dealer both had failed hour displays. Our dealer tells us the tachs used by Hunter are notorious for a failing the LCD hour display and a quick google of failed VDO tach engine hour display will confirm that. Some had temporary success disassembling the tach and re-seating the LCD connector cable. The tach needle moves okay I guess, but it takes it a second or two to actually decide to work. BTW - I had to trust the dealer's estimate of hours on the engine when we bought the boat.
After some research I figured out it was a VDO Marine Gauge OEM tach and called Continental (current owner I guess) and they referred me to their repair facility in North Carolina (Nichols Speedometer 336-273-2881). I talked to one of their techs who said they could repair the LCD for about $85 and mentioned their diagnostic equipment could read the current hours from the tach microcontroller memory and put that in a new tach if I wanted to go that route. The tech also said that erratic behavior on starting might indicate a failing meter and he would check that first before repairing the LCD to see if it would be better to simply replace the tach.
Dan
PS - Woody - you boat looks awesome and especially awesome in the water!
Our h36 has a Yanmar 3YM30 with a "new Type B" panel that uses pulses from the alternator stator to an OEM VDO tachometer and has a blank engine hour gauge as well. In fact, the two H36's we looked at ('07 and '08) at our dealer both had failed hour displays. Our dealer tells us the tachs used by Hunter are notorious for a failing the LCD hour display and a quick google of failed VDO tach engine hour display will confirm that. Some had temporary success disassembling the tach and re-seating the LCD connector cable. The tach needle moves okay I guess, but it takes it a second or two to actually decide to work. BTW - I had to trust the dealer's estimate of hours on the engine when we bought the boat.
After some research I figured out it was a VDO Marine Gauge OEM tach and called Continental (current owner I guess) and they referred me to their repair facility in North Carolina (Nichols Speedometer 336-273-2881). I talked to one of their techs who said they could repair the LCD for about $85 and mentioned their diagnostic equipment could read the current hours from the tach microcontroller memory and put that in a new tach if I wanted to go that route. The tech also said that erratic behavior on starting might indicate a failing meter and he would check that first before repairing the LCD to see if it would be better to simply replace the tach.
Dan
PS - Woody - you boat looks awesome and especially awesome in the water!
It is a vdo Tach and reads from then flywheel. I have a new tach but have not installed it because I didn't know if that would fix it and didn't want to tackle calibrating a new tach.
check your pick up on the flywheel/ bell housing for proper gap and cleanliness that may be part of the problem..it's a proximity switch sorta like an electronic eye but without the light shining it works on electric field that breaks every time the flywheel makes a rotation if the gap is wrong sometimes you get a weak signal or if it is real dirty could cause that
What do you mean by checking the gap? Do you mean taking the sending unit out? Two wires connect to a plastic unit that I asume is the sending unit. I hate to start unscrewing things from the engine as they have a tendency to break.
there is a gap like on a spark plug or ignition points between the end of the pickup switch (tach sensor/proximity switch) and the flywheel ...i don't have my manual with me but if memory serves me well it is .090 of an inch ......it is also possible that the switch wire has a broken place in it and working intermittently........i think it is a metric thread 18 mm .....this is a complicated way for a tach signal but to me is the best way and most accurate.... because you don't ever have a loose belt problem like on an alt and it is reading true engine rpms always ...that .090 of an inch may not be correct as i am doing this from memory and honestly i have the best forgetter in the world .....
i will add that if you find your tach sensor is bad ...you can get a replacement at a NAPA store...it won't be yanmar but but stewart warner and they com in the metric thread and are about $ 25.00 and for what its worth neither is the yanmar switch it is a vendor item to them and used as original equipment sorta like delco is to GM.....
Woodster, I also have the type B panel on my 3ym20 and have the same problem. When it does come on, intermittently, it registers the correct hours. My question: is the proximity switch on the flywheel/bell housing readily apparent? What do I look for?
Thanks,
Roland
s/v Fraulein II
that sounds like your display in your tach is acting up based you you saying that your hours are correct the tach sensor is sending the correct signal.... does that tach have and lcd display for the hours or is it a mechanical clock with tumbler numbers if its lcd it's more than likely in the tach display if your hours were not correct i then would look at the sender switch ...but first as alway look for a short in the wiring or a bad or corroded connection in the harness from the tach to the engine.... unplug all the connections one at a time and spray some contact cleaner in both halves and then plug them back together until you have done them all ...one thing i have learned over time is problems on electrical is always detective work first then repair after you have found the perpetrator
It's the lcd display. After I posted, I began thinking that if it actually was the sending unit, the hours would probably be wrong. I will take your advice and start from the receiving end and work back. Thanks.
Roland
s/v Fraulein II
Roland
s/v Fraulein II
Took your advice and installed an hour meter. No more screwing with the tach.
Sailgunner, before I go attempting to reinvent the wheel, where did you get your hour meter and how do you go about installing it? Thanks in advance.
Roland
s/v Fraulein II
Roland
s/v Fraulein II
9
I bought mine at a local marine store but you can get one cheaper on line (I paid $38). I went with a mechanical unit rather than LCD. It is really easy to install. Plus lead goes on the ignition switch (lead that is hot when engine is running) and negative to any ground you find. Use a volt meter to determine which is the correct connection on the ignition switch. This was a lot easier than replacing my tach and then not knowing if that would even fix it.
Roland,
Like you, I have the Type B panel with a non-functioning hour meter. I bought a Honeywell Hobbs Meter Model 85094-12 and mounted it at the bottom of the Type B panel. It was easy to install and pulled power/ground from the fuel meter.
Like you, I have the Type B panel with a non-functioning hour meter. I bought a Honeywell Hobbs Meter Model 85094-12 and mounted it at the bottom of the Type B panel. It was easy to install and pulled power/ground from the fuel meter.
Thanks to all for the advice. Been out of town for a while. Did have a great day sail on a tri in Cozumel a few days ago. Hernando Beacher, we need to round up Jim and go for a sail, soon.
I have the same "come and go" problem. My boat electrician, son-in-law told me it is a common LCD problem (age of display), I keep a general log of engine hours and when the Display show, it is very close to my records.
Since mine is built into the Tachometer , not an easy fix. I am looking for an alternate compatible Display.
Jim...
Just get a Hobbs meter and be done with it. About 35 bucks and two wires from your panel and you are good to go Almost as easy as hooking up a crystal set
I have the 3YM30 and they don't use a fly wheel signal like the 3GM30 but use the alternator instead and my 2007 H-36 tach started going crazy and after much searching talked to VDO and they help me find a cheaper new VDO tach on line $100.00 the Yanmar Tach was $$$$$$$$$$ and guess what the new tach goes crazy but not as bad and tried a new alternator I found at a very good price on line and it helped so works much better but not 100% but way more better.
Nick
Nick