Hour meter stopped working

[lake side bob]

My 1989 Cat D3c LGP hour meter has stopped working under 3000 hours on it, is there a way to check if the electric wiring is bad, disconnected, with out disassembling the dash?
Would appreciate suggestions on what to look for.

 

[lake side bob]

My 1989 Cat D3c LGP hour meter has stopped working under 3000 hours on it, is there a way to check if the electric wiring is bad, disconnected, with out disassembling the dash?
Would appreciate suggestions on what to look for.

I have the repair manual it does not communicate any thing on how to check the hour meter.
I heard Cat's service technicians service manuals are far more detailed then the ones we operators can purchase so i am wondering if any Cat tech know how to find out what is wrong with the hour meter.
For starters where does the other end of the wire from the hour meter connect to the engine If I knew that I could look to see if the wire was disconnected fell off the mounting wire to engine. The wire was broke etc. I do not know where the wire for the hour meter connects to the power that would operate the meter.
Any comments?

 

[Delmer]

In '89, I'm GUESSING they used a simple hour meter that had only a power feed off the ignition circuit, ignition key on, hour meter runs. Ignition key off, hour meter doesn't run.

Anybody have a better guess?

 

[DMiller]

Some ran off Alternator circuit, thru a Oil pressure switch, some simple where as soon as starts charging would run, others worked off regulator side terminals. Without a service manual for this is all guessing game.

 

[Mark250]

here is an abbreviated schematic

 

[heymccall]

I've changed the mete on my '96 D4H 4 times in 8k hours.
Regardless of mechanical or digital meter, one wire is ground.
On mechanical meter, other wire is 24v when running.
On digital meter, one wire is 24v when running, and 3rd wire is 24v all the time, so the lcd is on even without the key in the machine.

 

[lake side bob]

Thank you for your reply.
This is what I have done.
I took the dash off the dozer left wires connected.
Tested the wire for the hour meter to alternator, result no power.
So I tried the power to the lights with a jumper wire to the hour meter and it worked (the hour meter).
So I have installed a wire from the light power to the hour meter power input terminal.
Put every thing back together.
Hour meter working again.
Thank you for reply's to my question.