Thread Tools Search this Thread Display Modes
Old 04-19-2011, 03:10 PM   #1
phishown's Avatar
Join Date: Aug 2010
Posts: 17
Help with tach issues???

When I purchased the boat the tachs did not work and was told the previous owner just replaced the alternator with a 100 amp alternator and put an external smart regulator *SAR 12 for the batteries. *I notice that *there is no R terminal on the back of the new alternator and the tach wire was unplugged because of this. *I had an R terminal installed on the alternator so I could hook my tachs back up with no luck in running the tachs. *I am only getting 2 volts out of the R terminal along with 2 volts at the back of the tachs. * I took the alternator back to shop today and they tested everything and all was fine and they stated I should be getting a constant 7 volts out of the R terminal. *The tach only moves slightly when reved up. *Could the smart regulator be shutting the alternator down because the batteries are full? I am usually pretty good with 12 volts....I even had a mechanic look at everything last night with no luck. *Any ideas?
phishown is offline   Reply With Quote
Old 04-19-2011, 08:03 PM   #2
TF Site Team
koliver's Avatar
City: Saltspring Island
Vessel Name: Retreat
Vessel Model: C&L 44
Join Date: Nov 2007
Posts: 4,340
RE: Help with tach issues???


Exactly the problem that I have, with a smart reg on the port side and a dumb one on the Starboard side, I only get tach on port if the reg stops putting amps into the batteries. this usually only happens near the end of a voyage, after 2 or 3 hours running. I have become adept at guessing when both engines are at the same rpm, from the harmonics, so I really only need one operating tach. Single engine would be more of a test. So far I am 11 years with this situation and I haven't needed to do anything about it.
koliver is online now   Reply With Quote
Old 04-20-2011, 05:14 AM   #3
phishown's Avatar
Join Date: Aug 2010
Posts: 17
RE: Help with tach issues???

I will try the microwave trick.....thanks for your help it definately sounds like the smart regulator is to blame. *

phishown is offline   Reply With Quote
Old 04-20-2011, 07:09 AM   #4
TF Site Team
FlyWright's Avatar
City: California Delta
Vessel Name: FlyWright
Vessel Model: 1977 Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 13,512
RE: Help with tach issues???

I have been battling the same issues with my port tach. When the ammeter load is up, the tach works better...sometimes spot on, sometimes 300 RPM slow. I was planning to replace that alternator with a 100A Balmar with smart regulator, but maybe that won't fix my problem. Does anyone know why this happens? Is there a reliable fix?
FlyWright is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Concrete Ballast Issues Capt Dan Willard | Fales 4 07-21-2011 08:41 PM
Racor Issues........ hollywood8118 Power Systems 3 09-08-2010 12:41 PM
Lehman Starting Issues AllanY Power Systems 86 09-01-2010 11:55 AM
ME hours counter on tach out Keith Electrical and Electronics & Navigation 3 10-27-2008 05:21 AM

» Trawler Port Captains
Port Captains are TF volunteers who can serve as local guides or assist with local arrangements and information. Search below to locate Port Captains near your destination. To learn more about this program read here: TF Port Captain Program

All times are GMT -5. The time now is 02:26 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012