Tachometer

[Tom Lanzilli]

I have a M-35B in a Catalina 34 and The tachometer is not functioning correctly.  Here is the status of my troubleshooting and I would appreciate your advice:

- Wire to SEND terminal on Tach to Alt  = good 0 ohms no ground.
- Voltage at the Send Terminal on the tach with engine running and connected to alt = 8.3 V
- When Key is turned on the tach responds slightly to say 800 rpm.  Upon start gage needle immediately travels fully clockwise to what  appears to be a hard stop.
- Voltage at IGN and GND on tachometer is battery voltage.
- Battery charging 14V full batteries when running
- No tampering with the calibration settings has been made – paint marks from factory intact.

All looks fine with the wiring – 3 year old boat – no corrosion at all.

My diagnosis is the tach is bad – am I right?  Is there something else to check out?

[Mike Denest]

My tach works when the engine is running but at static (engine off) reads 500rpm.  Guess it needs to be replaced.

[Stu Jackson]

Tom

Not a direct answer to your question, but references for all

1.  Teleflex troubleshooting guide - I found at: http://www.teleflexmarine.com/cgi-bin/frameset2.cgi?site=gauges&type=us&link2=1047     Click on Troubleshooting on the left pane.  Under Installation Instructions, right side, scroll down to Tachs, Diesel Alternator, there is an instruction manual, the third page shows the voltages you should expect across the lines.   Don't know if you've seen this. 

2.  Like anything electrical, check the connections, especially the ground.

3.  As previously and frequently noted, tachs don't work when the batteries are fully charged.  We discussed that earlier this week, at:  http://c34.org/bbs/index.php?topic=2953.0      I didn't know from your post whether that was a contributing issue for you, or if you were just questioning the the measurements you had made at your tach connections.

[Stu Jackson]

Thanks, Tom, for providing us with the manuals   Much appreciated.

[Ron Hill]

Tom : From the description of the symptoms, I'll say you need a new tach instrument.  I'd call teleflex and talk to their customer service to confirm, before buying a new one.

Mike : If you turn on the key switch and your tach needle goes to "0" then the tach needle was not properly staked and your tach is OK.   

[Tom Lanzilli]

Thanks for the help, I did write Westerbake customer service to get their opinion, I will also call Teleflex.


You are welcome for the manuals.

[Tom Lanzilli]

My conclusion is the tach is bad; the Teleflex site was helpful.  I assume the tach is made by Teleflex, however Westerbeck claims it is made by Seaward for Catalina.  Would anyone know which it is and is there a parts outlet which can give me a good price?  Westerbeck wants about $165 for the device.

[Tom Soko]

Tom,
Both you and Westerbeke are right.  The tach is manufactured by Teleflex, and the engine panel is assembled by Seaward Products for Catalina.  Not sure where the best deal is for a new tach.

[Stu Jackson]

The "best" deal might be West Marine or Defender.  When our voltmeter went years ago, I didn't bother with OEM stuff, but just bought one.  Seaward may well buy them from Teleflex.  Please, let us know what the best deal is.

[Ron Hill]

Tom : You might try Boat US special order and see if they will give you a 10% special order discount.  Have you called Seaward to see what their cost would be?  Otherwise you just might have to pay their price.