Oil & Fuel TN65 oil light coming on

RHughes · Apr 5, 2011

Had a strange problem crop up while doing some box blade work this last weekend. When I started up, the oil light came on and almost immediately went out, just like it should when the oil pressure builds up. About a half an hour into the work the oil light came back on and stayed on. No strange engine noises and no sign of overheating. I shut down, checked the oil level which was fine, and checked for any obvious leaks; didn't find any. When I cranked back up, the light went out... for a while, then came back on.
As best I can tell it appears to be coming on when the tractor warms up. There are no signs of a leak and the tractor isn't using oil. I don't see any signs of the oil pan being overfull or losing coolant so I don't think there's a problem with the block of heads.

Has anyone seem any similar situation with a TN65 or any of the TN series?? I hate to haul the thing 50 miles to the dealer if there's something else I can check or replace in my own shop.

Thanks!

banjodunn · Apr 5, 2011

G'day my guess is a bad sender unit, the best way to check would be to 'T' a gauge into he circuit where the sender unit is and operate the unit until the light comes on and take note of the oil pressure on the gauge, if this is ok then leave the tractor running and disconnect the wire from the sender unit if the light goes out it is a bad sender if it stays on then you have a wiring prob. Best of luck

Jon

RHughes · Apr 12, 2011

Well, checked out the oil pressure last weekend with a mechanical gauge. It looks like a faulty sender or ground is *definitely* the problem Over an hour of testing and the system holds a steady 50psi at 2200 RPM, 42 psi at 1500, and 20 psi at 600 RPM. Can't find any fault there!
I love it when the fix is $13.99 instead of $1399.