656D Oil Pressure Send

Gents:

I have been working through a bunch of issues on my Farmall 656 D.

Rebuilt the shift mechanism. What a difference! I can find all 6 gears easily. I ended up replacing some pins, and welding up a couple of linkages, but mostly just cleaned and lubed everything.

I also installed a new fuel gauge cluster. I have everything working but the oil pressure. My oil pressure gauge is set up as follows:

On the left side of the engine, near the breather is a small rubber hose tapped into the side of the block. It runs back to a sub panel, located on the left side of the "dash", in front of the shift linkages for the tranny. This sub panel is normally hidden by the shift linkage cover.

There are two steam gauges - a water temp and oil pressure gauge. Both gauges have been drilled to allow a high temp "stop" that is wired (to ground) and actuates the warning lights.

The water temp probe in my original gauge was cut off. There is no "water temp" idiot light and of course, the wire on the lower steam gauge was cut off and goes nowhere.

The oil pressure gauge isn't working - which of course makes me nervous, but the tractor has been running great for a long time.

Is this subpanel normal or some weird modification? Doesn't show up in my parts manual. I was looking for an oil pressure sending unit, but it doesn't exist on my tractor. I am going to pull the sub panel tomorrow and see if I can run down the oil pressure gauge issue and then figure out how to make it work correctly. I prefer real gauges, but it would be nice to know that the idiot light works just in case.

Thanks.

Sounds like you have a murphy switch safety shutdown system that isn't working. Unless the tractor is going to be operated unattended, get rid of it and watch your gauges and lights.

As far as the oil pressure switch to operate the idiot light, NAPA OP6079 will work. Doesn't look original but works fine. Look for a light gray wire in the wiring harness and connect it to the oil pressure switch.

Tractorman:

Thank you again for the help.

My wiring harness is a mess. I simplified it a bunch yesterday because there are so many old & frayed wires. The prior owner put an alternator on it and cobbled a new "harness" for the lights so it isn't original to start with.

The starter always "dragged" on this tractor but now really turns it over. Amazing what resistance from old corroded wires will do.

I need the tractor for baling, but am going to make a new wiring harness for it in the fall.

In the meantime, I am off to NAPA to pick up a sending unit & bulbs. I will get the idiot lights working at the least.

Thanks again for all your help on this!

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