Hour Meter Stopped Working

[mmranch]

I recently split my TYM T603 tractor to repair some hyd oil leaks in the input shaft area. All this went fine and the tractor is working great.


But one thing I noticed the other day is the mechanical hour meter in the instrument cluster has stopped working. All other instruments are working fine but the hour meter has stopped turning.

No electrical connections inside the tractor were disconnected during the split. No wiring harness was touched inside. There are 3 wire harness connections that connect to the back of the self contained instrument cluster box. They are all in place and tight.


There is a main wire harness connection at the firewall with about 50 pins on it. This WAS disconnected during the split. Of course, it has been re-connected and all electrical items are working fine in the tractor... except the hour meter.

All I can think of is the one pin in the main wire harness connector that relates to the hour meter is not happy and I guess I'll try disconnecting and reconnecting the connection. But it's very hard to get to, particularly with the FEL in place. And I've got a lot of work to do with the tractor and don't relish messing with the hour meter at the moment.

Has anyone else had their hour meter stop working like this?

Thanks for any ideas.

 

[mike48130]

Not familiar with that tractor, but if it has the mechanical cable then odds it is ran off the spedo. You should be able to tell if it mechanical or digital. I assume the spedo is working when you said all other gauges work. That would make it internal, and maybe fixable if you tear the cluster apart. Posibly just dirty. Mechanical ones are always know to go bad, and a lot of digital ones too.

 

[RNeumann]

Yep- if it is mechanical the cable may not have been seated correctly? Typically the newish ones are electric so I’m confused as to the type of meter. If it’s electrical all it needs for the meter signal is power when running (typically the “run” position on the ignition).

 

[mmranch]

Thanks for the ideas.

When you look at the hour meter, it has mechanical wheels that spin with the hour numbers on the wheels. But there are only electrical wires that come to the back of the instrument cluster box... there is no mechanical cable that drives the mechanical wheels of the hour meter. So it is driven by electrical pulses.

This instrument cluster only shows gauges for fuel, tach, temp, and hours (plus a bunch of lights along the bottom for glow plugs, etc.)

Thanks again.

 

[flyerdan]

If possible, you need to determine if the meter is driven by ignition switch fed power, or oil pressure ground. If it's switch driven, it will rack up hours if the switch is inadvertently left on. A pressure switch only allows grounding when there is oil pressure, so hours only accrue when running.
Chances are there will only be power to it when the switch is on, so once you determine the power lead, ground the other and see if it works. It's possible that a ground strap might have got overlooked, or the big firewall connector could have gotten a bit of dirt in that pin socket.

 

[mini14]

i would just rewire it. simple, leave the ground attached just run a wire to a hot while running source

 

[Tx Jim]

Electric operated speed/hour meters I've had experience with get signal from sensor mounted on engine or from alternator.

 

[Tx Jim]

i would just rewire it. simple, leave the ground attached just run a wire to a hot while running source

I would be hesitant to "re-wire" the wiring on any newer tractor with ECU. Re-wiring could possibly cost a lot of $$$$$$.

 

[Diggin It]

There is a main wire harness connection at the firewall with about 50 pins on it. This WAS disconnected during the split. Of course, it has been re-connected and all electrical items are working fine in the tractor... except the hour meter.

Do you have, or can you get the Service Manual (at least the page(s) ) with the schematic/wiring diagram? That will tell you if that circuit even uses that large connector.

 

[mmranch]

Thanks for all the ideas!

When looking at the front of the instruments:

Fuel is on the left... tach and hour meter in the center... temp on the right.

When looking at the back of the instruments:

Medium size connector on the fuel side... small 4-wire connector in the center (tach/hour meter)... medium sized connector on the temp side.

The wires disappear into the instrument box and you can't see what they connect to. You can't see exactly what wires connect to the hour meter.

But I'm assuming the small 4-wire connector in the center which goes in near the tach/hour meter connects to the hour meter.


I found the wiring diagram and it shows the White, Black, White w/Red, and Orange wires of the 4-wire connector. The White w/Red and Orange wires are shown going to the Generator (after passing through the main firewall connector).

I will have to inspect my connections again and see if I've got something loose when I get some time. In the meantime, I've got to move some snow!

Thanks again.