BX25D Tachometer Doesn稚 Work

[Muleshooz]

Just took delivery on Saturday of my almost new 2016 BX25D with 42 hours on it.
Tach needle reads approx 500 RPM whether the engine is running or not. THE TACH DOES NOT WORK
All of the other gauges and idiot lights seem to be working fine.
I did notice that there was a little bit of condensation on the inside of the glass covering the Tach And other gauges.
Can someone help me to figure this out?

 

[diesel85]

I'm guessing that the electronics are shorted out from the ingress of water and condensation.

Minimally you can check the connections.

I would contact the dealer (I'm assuming it was a dealer), and alert them of your issue. Most dealers will go out on the limb and make things right for you, especially if they know they'll have future sales and service from you.

 

[s219]

I believe it's a mechanical tach, so start by looking for the flexible shaft running out of the back of the dash and trace it to the motor, make sure it's connected on that end. If that looks good, trace it back to the dash and make sure it's connected to the instrument panel properly. If none of that works, may need to replace parts. This may also affect the hour meter, not sure on that tractor.

 

[David_Kb7uns]

Very few of the new Kubota tractors use a mechanical drive tach. If it is a digital display dash it is electronic tachometer.

The BX tach uses the raw waveform off the alternator, the new alternators have an added pin on the plug for picking up that signal.

Usually there needs to be some type of setup in the dash so that the pulley ratio and the number of poles on the alternator can be compensated for. The moisture in the display is probably the problem.

David

 

[mljenkins]

Very few of the new Kubota tractors use a mechanical drive tach. If it is a digital display dash it is electronic tachometer.

The BX tach uses the raw waveform off the alternator, the new alternators have an added pin on the plug for picking up that signal.

Usually there needs to be some type of setup in the dash so that the pulley ratio and the number of poles on the alternator can be compensated for. The moisture in the display is probably the problem.

David

Just a thought, if it is off the alternator then the op should check that connection. Once my last tractor, a NH had a similar issue. The issue occurred after a limb poked in and hit the hose going to the steering reservoir and fluid went everywhere including on the alternator. After it dried up after an hour or so it started working again.

Point being if it is electronic definitely check around the alternator for a disconnected or damaged wire as it could be a simple fix (crossing fingers for you).

 

[David_Kb7uns]

The extra pin is with the other 2 connections for the field on the alternator , if the alternator is working unlikely the one low current signal pin failed.

But if there is moisture in the dash module, very good likely that the amplifier and counter circuit is shorted out. Especially if it is stuck at a position other then zero

There are more threads around about moisture in the gauges.

David

 

[dragoneggs]

My dash module collected significant condensation and finally the gauges failed. I was always careful not to directly spray but our high humidity, light rain, and dew point I guess, finally killed it at about 3 years and 300 hrs. The new module was about $200 IIRC, and it is performing better but not completely water tight for some reason. Maybe the only disappointing thing on my BX.

 

[David_Kb7uns]

I am thinking that if you can open the modules up maybe able to spray a coating on the circuit boards to waterproof them. The gauge cluster on my quad was clouding up and put silicon grease around the button and the O ring seal and it kept the moisture out.

David

 

[diesel85]

I highly recommend this: Crc Urethane Seal Coat Coating, Clear, 16 oz. 18411 | Zoro.com

I use this stuff when I do re-work on boards for outdoor/high humidity applications.

 

[dragoneggs]

The BX dash module is not friendly to opening up IIRC. It is a sealed box (well suppose to be) and even if you take the glass face off you still don't have access to the guts behind the dials. I guess I didn't do a full dissection before tossing for a replacement but it didn't seem obvious or I am sure I would have.