Combination speedometer / tachometer

Discussion in 'General Harley Davidson Topic' started by DCLARKE, Jun 2, 2013.


    DCLARKE Member

    I wonder why some of the newer Harleys do not come with Tachometers. I am thinking of switching mine out to the new Harley combination speedo / tach, part # 70900070A. I see they are on the new Road King CVO's. They look really nice. Does anyone know if it is worth the coins to change out? Thanks for any input.
  2. mlemay

    mlemay Member

    I've been thinking of doing the same thing. Maybe a good mod to do this winter in the garage.
  3. SilverFoXD

    SilverFoXD Junior Member Contributor

    I'm currently running the 4" combo on my '07 Dyna. Mixed feeling on it, like the display better but not all features in the speedo are supported by the '07 ECM plus we lost the 6th gear indicator. Your '08 would also not support all features.

    If you go with it you're pretty much stuck with the unit. The initialization is simple and you get about 50 miles before it locks to your unique bike. I've switched back and forth between the stock speedo and the combo and right now the combo is showing fewer miles than are on the bike, and producing a diagnostic TSM/TSSM error U1097. I don't know if this error will go away, it clears OK but comes back. The original unit never showed the error, even when off the bike and then returned.

    Only operational problem is the random tendency to switch displays. I like to to ride with the Trip A showing and the unit likes to switch to the odo reading. No rhyme or reason as to when, sometimes twice within five miles then not at all for the next 100. Also got three gear displays shown, two for 5th and one for 6th, when the instructions said the gear indicator wouldn't work. The 600 colors are nice but I wasn't quick enough on the button to get other than the default values.

    On a new bike I think the combo unit would be a great addition. On an older, maybe not. Just my 2ยข.
  4. lorne

    lorne Senior Member

    i have a digital on my softail...and the analog on the roadking....i much prefer the analog....i love the idea of the tach and if i had a bike without one i would probably install one.....just because it is a force of habit to look at it
  5. biscuit

    biscuit Junior Member

    I bought a combination speedo/tacho for my '08 Deluxe a few years back(p/n 74717-10)-it has a large digital speed display in the centre of the unit and an analogue tacho with a needle that sweeps around the outside face of the unit.I think it's great. I have no trouble reading the speed display and the engine RPM's are equally readable.I previously had a Zippers unit that was useless in daylight-worst part i think i've ever bought.Not so this unit.

    Mine has all the usual Harley 'idiot' lights on the face(the very same ones that appear on the stock unit) and they all work as they should.I've had no trouble at all with mine

    The only adjustability built into my unit is the ability to toggle between MPH or KPH.Thats it.-No colour changing,no dimming capabilities,nothing.It has the usual time display,trip functions and D.T.E-basic stuff.

    From memory,it took about 15-20 minutes to fit-a figure which can be shortened considerably if you don't care about your paintwork.A real easy job.Plugged straight in.

    Yours is quite different to mine,but i'd imagine the premise is much the same.
    I think they're a great idea.
  6. doctor727

    doctor727 Active Member

    I just put the combo on my 04 Heritage. Other than losing some of the features due to the age of my ride, I have no complaints. All the features that the 04 supports work great. The color choices make it specialized as you see fit. I like the tach feature, that's why I changed, the best. I have about 600 miles on it and so far, :D.
  7. Blue Wide Glide

    Blue Wide Glide Junior Member

    Don't forget that the warranty starts when you buy it, and if you install one, like I did over the winter, by the time you can properly test it the warranty is over.
  8. RibEye

    RibEye Junior Member

    I've had a combo on my '03 RKC for just over 10K miles. I simply could not see going on without a tach. I've heard that others had trouble with them. I believe that is because the installations were faulty. One line has to be added to the speedo connector. The pin does not go into the connector easily. If it does not go fully in, it can work its way out and the tach will quit working. Some folks damage the wire at the pin, trying to get the pin in, requiring the purchase of a pricey pin extractor, and a new pin and crimper.

    Good luck,
    Rich P
  9. Blue Wide Glide

    Blue Wide Glide Junior Member

    The faceplate on my first unit warped when it got hot, and trapped the speedo needle at 65 mph, I had to go thru HD to get a replacement because I installed it over the winter, the warranty was expired, and it began messing up at Bike Week in Daytona. The replacement unit I have now goes crazy when it gets hot. the tachometer shows 3,500 at idle, 6,000 at 45 mph. or sometimes even higher, and stops moving altogether. It only does this when the sun is shining on it for a while. Sometimes the speedometer even stops working altogether.
    Does that sound like a faulty installation??
  10. RibEye

    RibEye Junior Member

    It could be. If the pin added to the connector is not fully seated, or there is an intermittent connection somewhere in the tach signal lines, you could get multiple extraneous pulses from vibration (signals are generally pulled up or down at their destinations). This condition may be revealed when the area around the intermittent connection is heated, resulting in a bit of expansion. The intermittent connection could be a bad internal solder joint. I can't tell from here. Like any product, bad ones can get out.

    My statement was not intended to negate issues "all" others may have had. My intent was to show that some folks have had issues due to faulty installation, and to show how the installation could be corrected. Some issues are correctable by users. I have been able to help some in this regard.

    I replaced a bad original speedo with my new combo unit. Bad units do exist.

    Good luck,
    Rich P