Tach's are irratic.

Discussion in 'Sport Cruisers' started by John boat, Feb 16, 2020.

  1. John boat

    John boat New Member

    4
    Jan 25, 2020
    2003 SUNDANCER 300
    350 MAG MPI W/BRAVO III DRIVES
    So my 2003 sundancer 300 tach's are jumping. If I tap on them they will jump, also when the engines have just started. I have pulled the bezel and checked the connections and they seem tight. I don't see a switch on the back to change any settings like I have read on other posts. if I move the plug on the back of the gauge I can get it to move as well. Is it an internal problem? Can I service the gauge myself? Thoughts?
     
    Express 390 likes this.
  2. dwna1a

    dwna1a Well-Known Member GOLD Sponsor

    Apr 23, 2012
    James River
    88 Weekender 300 "Seahorse"
    Twins 350
    Check and clean your ground wire for the tach
     
  3. rlynch03

    rlynch03 Active Member GOLD Sponsor

    245
    May 16, 2019
    Annapolis, MD
    07 52 Sedan Bridge, 2019 Brig Falcon 360HT-30HP Honda, 2003 16' Dauntless
    Cummins QSM 11 660 HP w/ ZF 325-1A
    My last boat had the same issue... I would remove the wires from the back of the tach’s and spray with Electrical Contact Spray.

    This would cure the problem for a few months or more.
     
  4. Express 390

    Express 390 Active Member GOLD Sponsor

    445
    Sep 14, 2018
    South Shore of Long Island NY
    1986 SeaRay 390 EC
    1993 SeaRay 290 DA single 7.4 /Bravo 2
    1992 SeaRay 230 DA 4.3LX Alfa drive
    Twin 454 Crusaders inboards 4 blades
    This seem's to be an issue with the Tach's SeaRay uses this was an issue i fort with every year no matter what i did.i finally replace them with Aetna Digital tach's. The Issue Is No More ! 2257E562-C448-4F45-87E2-098289EB2440.jpeg
     
  5. John boat

    John boat New Member

    4
    Jan 25, 2020
    2003 SUNDANCER 300
    350 MAG MPI W/BRAVO III DRIVES
    I have several technicians tell me I can send the gauges out to be repaired..... has anyone repaired them on their own?
     
    Express 390 likes this.
  6. Express 390

    Express 390 Active Member GOLD Sponsor

    445
    Sep 14, 2018
    South Shore of Long Island NY
    1986 SeaRay 390 EC
    1993 SeaRay 290 DA single 7.4 /Bravo 2
    1992 SeaRay 230 DA 4.3LX Alfa drive
    Twin 454 Crusaders inboards 4 blades
    I don't know what you could possibly do to them!

    Also Welcome Aboard Hopefully someone else will chime in and give you more info.
     
  7. atrick

    atrick Active Member

    338
    Mar 4, 2017
    Penna
    1995 searay 290 Sundancer
    1990 21 maxum
    Twin 4.3 mercrusers with alpha one genII drives
    305 chevy with a alpha one drive
    Its not just searays, my maxum tach does it too!
     
  8. Express 390

    Express 390 Active Member GOLD Sponsor

    445
    Sep 14, 2018
    South Shore of Long Island NY
    1986 SeaRay 390 EC
    1993 SeaRay 290 DA single 7.4 /Bravo 2
    1992 SeaRay 230 DA 4.3LX Alfa drive
    Twin 454 Crusaders inboards 4 blades
    Both are made by Brunswick corp.
     
  9. fwebster

    fwebster Well-Known Member TECHNICAL Contributor PLATINUM Sponsor

    Oct 6, 2006
    Middle Tennessee ; Panama City Beach, FL
    1996 450DA
    3116 Caterpillars
    This is a common problem with Teleflex techs, who was the vendor for Sea Ray. They do have the ability to repair techs, but they cannot reset the hours and the repair cost is more than the cost of a new tach......roughly $190. After 3 sets of Teleflex replacements, I gave up and switched to Aetna digital electronic techs.

    And, no, the techs are not user serviceable.
     
  10. John boat

    John boat New Member

    4
    Jan 25, 2020
    2003 SUNDANCER 300
    350 MAG MPI W/BRAVO III DRIVES
    What are my options? Replace all the gauges? What Gauges will work with the single plug connections like I have? Can I just replace the Tach's? I don't want to start making it look like a hack job.
     
  11. NotHerDecision

    NotHerDecision Well-Known Member PLATINUM Sponsor

    Jun 28, 2016
    Houston, Texas
    2001 Sea Ray 460 Sundancer
    2014 Seadoo 155 LTD
    2105 Seadoo 130 SE
    2013 Mercury Dinghy
    Cummins 6CTA 8.3L
    Aetna tachs are plug and play or you can buy new versions of what you have but they too will fail.
     
  12. electricaldoctor

    electricaldoctor Well-Known Member TECHNICAL Contributor PLATINUM Sponsor

    May 14, 2008
    Thousand Islands, Rockport, Ontario.
    1988 390 EC
    454 Mercruiser Gassers
    Try switching the selector switch on the back of your tachs back and forth a few times to wipe the contacts and return them to the 8 cylinder setting.
     
    joeyleggz, JVM225 and NorCal Boater like this.
  13. fwebster

    fwebster Well-Known Member TECHNICAL Contributor PLATINUM Sponsor

    Oct 6, 2006
    Middle Tennessee ; Panama City Beach, FL
    1996 450DA
    3116 Caterpillars

    Ssuggest you re-read post #9:

    Your options are 1)remove the factory tachs and send them back to Telefles for repair. You will need to remove the gauge panel and remove the tachs from the back side. You will be running your boat without tachs until you get the repaired ones back.

    2) replace the tachs
    a. with a factory replacement - costs about $190 per tach
    b. with Aetna digital techs. May require a special bezel to fill the hole. This is a plug and play hook up since the Aetnas use the same 3 wires the factory techs do. This is also a permanent fix since Aetnas don't fail.
    c. some brand of aftermarket tach that you like - wiring changes and difficulty depends upon the brand of aftermarket tach you choose.

    Any fix to factory tachs like flipping the various switches or even sending them in for repair should be considered temporary because all that happens is creating fresh contacts on corroded internal switch parts or replacing the internal switches with new ones that will eventually fail due to internal corrosion.

    Replacing the techs doesn't need to be a "hack job". On my 450DA, the factory gauge bezels were black and Aetna sells a black tach and a black bezel.



    [​IMG]
     
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  14. Express 390

    Express 390 Active Member GOLD Sponsor

    445
    Sep 14, 2018
    South Shore of Long Island NY
    1986 SeaRay 390 EC
    1993 SeaRay 290 DA single 7.4 /Bravo 2
    1992 SeaRay 230 DA 4.3LX Alfa drive
    Twin 454 Crusaders inboards 4 blades
    I installed the black also Looks Great the best thing i ever did IMG_1213.jpeg IMG_1213.jpeg
     
  15. JVM225

    JVM225 Well-Known Member GOLD Sponsor

    Apr 8, 2008
    Farmingdale, NY
    2002 410 Sundancer, Monaco Edition.
    3126 Cats.
    That usually works!
    The starboard tach in my old boat had to be done at the beginning of the season every year.
    I did it to the starboard tach on this boat 3 years ago and so far so good.
    Aetna’s Ray wishlist though. The Aetna tachs are priced fairly butI just have to bring myself to spend the money on a new dash panel to fit them or come up with a suitable cost effective alternative
     
  16. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    My tachs were closee but there was a 125-300 rpm split. got tired of guessing what the actual RPM was so I bought the Aetna’s. Making a bezel was easy. Tools and materials from any hardware store and a little effort produced these.

    Not perfect and not my final panel, but allowed me to get them installed with out the expense of a new panel. I will do the new panel sometime in the near future.

    here’s the how to..

    http://www.clubsearay.com/index.php?threads/diy-aetna-tach-bezels-5-4.95904/
     
  17. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    And for the record...worth the $$$.
     
  18. The Bill Collector

    The Bill Collector Well-Known Member GOLD Sponsor

    Jun 2, 2008
    Tacoma, WA
    1998 450 Sundancer, Achilles dinghy
    3126 Cat's
    I have had issues with my tachs in the past and it seems it's the starboard one, but anyway I have pulled the dash panel off and removed the wires, sanded the contacts lightly, dressed with dielectric gel and re-assembled. In the E.R. my engines have a wiring harness connector, which I have disconnected sanded the contacts lightly, dressed with dielectric gel and re-connected. This has solved the problem several times over the 13 years I have had the boat.
     
    John boat and JVM225 like this.

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