Here is my agony problem.
I have a Z710A that I have upgraded with Volt gauge and Oil Pressure gauge. The Ztrak runs with a Kohler 23 hp V-Twin. I had no problem installing the Faria brand Volt gauge and the wiring set-up. Not with the Faria oil pressure gauge situation, as I have tried three 0-80 PSI sending units to no avail.
Here is how I have the oil pressure gauge wired-up.
1. Hot (red 16 gage wire) to the 12 volt "hot" wire when the key is in the "on" position to the "I" (ignition) post on the gauge.
2. Ground (black 16 gage wire) from the black ground cable on the engine block to the "G" post on the gauge.
3. Sendor unit (dk.blue 16 gage wire) from the sending unit to the "S" post on the gauge.
NOTE: When I first installed the gauge the gauge read about 55 PSI for about one hour of mowing, and the gauge needle fluttered and went to "zero". I re-checked my wiring to make sure all was tight and blight. So, I removed the sending unit and installed a new one. Now, when I turn the key on to "Start" the tractor, the gauge reads "zero" and sometimes the needle may read about 35 PSI and fall back to zero on the gauge.
I ordered a new Faria 0-80 PSI gauge and installed it. I get the same reaction on the new gauge and nothing else.. I've re-checked all the wiring and all tests out good.
To install a Oil Pressure gauge and sending unit, I had to installed a "sandwich adapter" between the engine flange and the oil filter. It is aluminum material and seems to be very high quality product. I don't think that is the problem. I think my problem may be the "grounding" of the sending switch that the gauge is connected to and not getting good ground.
Anyone have a better idea if they have this set-up on their John Deere Ztract mower.