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speedo/tach nightmare

weblefty

Member
I have a 00 FXDX and I am absloutely stumped by this problem. It is multi-faceted so bullet points will probably work best.

1. No tach at all, but has power (illuminated)

2. I have speedo up until a certain RPM, then quits, but still has power (illuminated). Odometer also quits at this stage.

3. When the above happens, engine light illuminates. When the rpm's go down below the magic rpm line, engine light goes off. I dont know what the rpm is that triggers all of this, but Im going to guess around 2200-2500. If im in first, it stops at about 10mph. I can cruise up until about 40mph in 3rd as long as I shift there at a low speed as to keep the rpm's down.

4. Pulled diagnostic codes and it says i have low/high battery voltage (not true) also says I have a dead rear cyliner (not true, bike runs fine).

5. I dont think its the TSM. I pulled the codes on those and the lights dont indicate any codes, historic or otherwise.

6. I did the speedo diagnostics thing where you turn the key on off on off etc and hold down the trip button. The needle does not sweep and I get the code that says its in diagnostic mode 1-10 and then its says "cal" after you cycle through all of it.

In short, I am out of ideas and was wondering if anyone has experienced similar problems. Other than this, the bike seems to work great except for some slight back fire on high rev down shift. The bike sat for a long time before I bought it and I am still working out the Harley kinks. I appreciate all the help and if I can be if any assistance at all, please dont hesitate to ask.
 
Since the bike sat for a while you might try checking both battery cables for corosion and make sure they are clean and tight. Do you know how old the battery is and if it had a battery tender attached. Battery should have 12.7 when not running no load.
 
Yeah. First thing I checked. Battery is brand new and so are the cables. Seems as though it is a voltage problem but I cant find a reason to say it is for sure. I am getting the proper readings coming off the battery so i am at a loss. Thanks for the reply.
 
I checked the it with a voltmeter. Reads just above 12 volts. Is that a thorough enough test or should I bring it back in to the shop?
 
I checked the it with a voltmeter. Reads just above 12 volts. Is that a thorough enough test or should I bring it back in to the shop?

The shop should be able to load test it. If it's good you can eliminate that as a problem.
 
I agree with all above. Its a voltage or grounding issue.

Bodeen
 
I checked the it with a voltmeter. Reads just above 12 volts. Is that a thorough enough test or should I bring it back in to the shop?

Full charged battery will be 12.7 volts, I doubt 12 volts would pass a load test
 
4. Pulled diagnostic codes and it says i have low/high battery voltage (not true)

Did you actually place a voltmeter across the battery and check what the Peak voltage of the charging system was with the RPM above 3K.? Sounds like the regulator may not be limiting the voltage as it should. Check to see if it's going above 14.5 volts by using a meter and hold the RPM in the 3.5K range.
Usually there are safety circuits in speedo's, ECM etc that will "crowbar" and protect the unit from over voltage.

It is simple to check & worth a try.
 
Did you actually place a voltmeter across the battery and check what the Peak voltage of the charging system was with the RPM above 3K.? Sounds like the regulator may not be limiting the voltage as it should. Check to see if it's going above 14.5 volts by using a meter and hold the RPM in the 3.5K range.
Usually there are safety circuits in speedo's, ECM etc that will "crowbar" and protect the unit from over voltage.

It is simple to check & worth a try.


Ok. Thanks for the advice. Up to this point I have just been checking it with the motor off. The thing that is confusing me is the goofy codes and the fact that it works up until that specific RPM and then, it' sjust the needle that stops. Speedo lights stay on. There are so many factors to consider its like nailing jello to the wall.
 
Nailing jello to the wall! This has to be one of the best descriptions I have ever read concerning electronic problems. Thanks Weblefty
 
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