Tach not working in International bus

[Clayton]

My tach doesn't work in my 96 International 3800 with a diesel DT466(mechanical). I took the gauges out and inspected the connections ect and it looks good. And all the other gauges are good... I was thinking there must be a sensor or something to check. Any advice?

[cowlitzcoach]

It all depends upon how the tachometer gets the signal from the engine.

Some were mechanical that used a speedometer cable to turn the needle.

Some used the same drive unit a mechanical tach used but it turned an electric generator that moved the needle.

And some others used electronics that moved the needle.

Because of the vintage of your bus it could have been any one of those three.

Once you determine where and how the signal goes to the dashboard you will be better able to diagnose why the needle isn't moving.

[Clayton]

Its not a mechanical tach. Its electronic.

[Booyah45828]

If it's electric, there might be a magnetic pickup sender on the flywheel housing for it. You can check that for resistance and how much voltage it has when running. My guess though is that it's in your cluster. Those seem to fail all the time and there are numerous write ups and how to videos on fixing it.

[Clayton]

Im certain its not the cluster. I seen the write ups and had my cluster apart. Also its just the tach, which just sits at 0. I will look for that flywheel sensor. Not sure what to look for though.

[brokedown]

Do your gauges sweep when you turn the bus on?

[jazty]

The tachometer in my bus didn't work when I bought it. Turned out to be that the DIP switches were set improperly (mine needed to be set to Data Link). Check out this post from CadillacKid for photos of the settings: http://www.skoolie.net/forums/f11/th...tml#post150821

[Clayton]

Originally Posted by brokedown

Do your gauges sweep when you turn the bus on?

Yes it does sweep when I turn it on.

[Clayton]

Originally Posted by jazty

The tachometer in my bus didn't work when I bought it. Turned out to be that the DIP switches were set improperly (mine needed to be set to Data Link). Check out this post from CadillacKid for photos of the settings: http://www.skoolie.net/forums/f11/th...tml#post150821

So you just moved that switch on top of the cluster as shown in the photo in your link?

[cadillackid]

the switches may be wrong, but also there should be a tach sensor down on the bellhousing if your cluster is the electronic type (that has the 2 banks of swithes)..

on that cluser the tach signal gets generated by a transducer on the bell housing that gets a signal off of the teeth on the flywheel.. it then sends the signal up to the cluster..

at least thats the way it is on my DT-360 all mechanical 1991 Bus.. on mine my tach registered but registered the incorrect RPM, and so I found the relevant manual anbd reset the switches.. ifits not reading at all i would tend to think that transducer perhaps has come loose or is missing...

I have heard rumors that on SOME DT-466's there was a plastic gear in the injection pump.. there would be a wire coming from the injection pump if thats the case.. i dont know about a 95 / 96 model...

im assuming you have the handle to pull on the dash to kill the engine? that was the fully mechanical DT's that used this...
-Christopher

[Clayton]

There is no lever to pull to kill it. But is defiantly a mechanical DT466.

[Clayton]

Here is one more, its the mechanical engine.

[jazty]

Originally Posted by Clayton

So you just moved that switch on top of the cluster as shown in the photo in your link?

Check your DIP switches and compare to the photo. What is it currently set at? If you're all mechanical and the switches are set to Reserved or Data Link then I'd expect there to be no reading on the tach, or max reading.. hard to say.

[cadillackid]

Originally Posted by Clayton

Here is one more, its the mechanical engine.

someone installed a nice shiny electric fuel solenoid on the front of your mechanical pump, (maybe from the factory)... thus no cabled lever on the dash for engine kill... idf your bus ever fails to start or shut off thats the first place id go to look!.. probably why that one is shiny... its new
-Christopher

[Clayton]

Originally Posted by jazty

Check your DIP switches and compare to the photo. What is it currently set at? If you're all mechanical and the switches are set to Reserved or Data Link then I'd expect there to be no reading on the tach, or max reading.. hard to say.

Here is a photo of them. The settings look correct, what do you think?

[Clayton]

Originally Posted by cadillackid

someone installed a nice shiny electric fuel solenoid on the front of your mechanical pump, (maybe from the factory)... thus no cabled lever on the dash for engine kill... idf your bus ever fails to start or shut off thats the first place id go to look!.. probably why that one is shiny... its new
-Christopher

That's good advice, thanks.

[jazty]

Yeah, the switches look good. 0-1-1 is for International mechanical engines AFAIK