TC29D Hour Meter

[jinman]

Well, I can't help you much more without a schematic. I think it is obvious that the signal from the alternator is not making it all the way to the instrument panel, but without a connector pinout off the schematic. I can't tell you where to look. It's really too bad that you don't have another tractor like yours to use as a go-by, but getting a manual (which you can get instantly in PDF form online) is the best bet.

New Holland Manuals & Parts

 

[depratt_equip]

Do you know what the reading should be coming out the alternator for the tach? Sorry this is an old thread but I never did get this fixed.

 

[jinman]

Jon, the tach output from pin "P" is a pulse off of one stator winding and represents 1/10 the speed the alternator is turning. That's what the Repair Manual says/shows for the tach input.

 

[lmoresco]

I also own a TC29D New Holland Diesel. I discovered that someone tried to fix it and had broken the thin wires that attach the hour meter inside the instrument panel (it's impossible to solder it back together. I found a new instrument panel and installed it. So I have an extra working gas gauge and a working tachometer if anyone needs either or both. BUT I still don't have a functional tach or hour meter. I traced the "GREEN" wire from pin 20 on the instrument panel connector to the alternator and that wire is good (it's not pink on my New Holland). For some reason now the red battery light stays on when the tractor is running. The only thing I've not replaced is the alternator (found one for $85). Does anyone know if that is what I should replace next or is there some other wire/component causing the non-responsive tach and hour meter and now the red battery light? Ran the tractor the other day for about 3 hours and the battery is charged to 12.4 volts ... not sure why the red battery light stays on.

 

[jinman]

Put a DC voltmeter set to the 20 vdc scale or higher on the big terminal on your starter where the battery cable attaches. Before starting, you should read battery voltage. Start the tractor and it should go to approximately 14 volts at that point. If it does not, it's just a matter of time until your battery will run down. When running, diesels don't pull much battery current. Only the fuel solenoid, a few relays, and instruments are powered. You can go a long time if your battery is fresh. A charged battery should read around 12.8 to 13 volts when the engine is shut off and not charging. Your alternator receives excitation from the battery through the charge light. When the alternator starts putting out voltage, it balances out the voltage from the battery so that the lamp does not have any current through it. It sure sounds to me like you have a failing alternator or bad wiring.

 

[Neil L]

Just found this thread, its raining so I won't be checking any thing outside today. I have a NH 1925 the tach works but not the hour meter. Any thoughts as to where to look first.
Thanks,
Neil

 

[jinman]

Neil, since your hourmeter is a mechanical counter, it could be gummed up. It might need cleaning, but it will require very careful disassembly and cleaning/inspection. The same signal runs the tach and hourmeter.

 

[lmoresco]

Put a DC voltmeter set to the 20 vdc scale or higher on the big terminal on your starter where the battery cable attaches. Before starting, you should read battery voltage. Start the tractor and it should go to approximately 14 volts at that point. If it does not, it's just a matter of time until your battery will run down. When running, diesels don't pull much battery current. Only the fuel solenoid, a few relays, and instruments are powered. You can go a long time if your battery is fresh. A charged battery should read around 12.8 to 13 volts when the engine is shut off and not charging. Your alternator receives excitation from the battery through the charge light. When the alternator starts putting out voltage, it balances out the voltage from the battery so that the lamp does not have any current through it. It sure sounds to me like you have a failing alternator or bad wiring.

sitting ... battery 12.34v... big terminal on starter 12.34V
running .. battery 12.04v ... big terminal on starter 12.04V
off ... battery 12.17 v ... big starter 12.17V

Sounds like the $85 for the new alternator is the next step.

 

[jinman]

Sounds like the $85 for the new alternator is the next step.

Yep, you can have it tested at an auto parts store like NAPA, but I think your alternator is toast.

 

[thescubasmith]

I have a 2000 model TC29 with the same problem. Tachometer and proof meter both stopped working at the same time. My model has a GREEN wire going from the alternator, opposite side of the alternator from the two charging wires, to a connector that plugs into the back of the instrument panel. All the wires on my tractor have ID numbers printed on the insulation. Check the number printed on the wire coming off the alternator and verify it's the same number on the wire at the panel. Using my Fluke meter I can count the pulses from the alternator at the instrument panel (You'll need a meter that measures frequency in Hz). I've ohm'd out the tach and the proof meter and both check good. I have checked every single diode, etc. on the board with the exception of the ICM (computer chip). I cannot check the chip but since a new instrument panel is over $700 (Messicks.com), I'm going to try to find a new chip and replace it in the circuit board. I will give an update when I have done this. However, I really hate to resort to just throwing parts at something. And I hate to let this machine beat me. SO if anyone has any further advice, I'd really, really appreciate hearing from you. This isn't at the top of my list of priorities, but I will post again when I've found the solution.