deankdx
The oil sender works resistance to ground.the ground is though the body of the sender as resistance changes oil pressure gauge changes. This being the case the wire should run from the sender to the cluster with no interference from supply or earth
“””””With it unplugged at both ends, cluster check if it has +12v there( shorted to 12v).””””””””
cluster un plugged and. Wire off the oil sender
depending if multi meter or just a test lamp I would check if +12v is being introduced in to the wire, wire is shorted to +12 volt
Multimeter - place the black lead to earth and the red lead on the wire, if you measure 12v the the wire is shorted to +12volt.
test lamp - connect the clip on the lead to earth and touch the probe on the wire, if it lights up the wire is shorted to +12v
“”””””Check if is grounded to -12v (shorted to Earth)”””””
Multimeter - place the red lead to +12v and the black lead to the wire, if you measure voltage the wire it is shorted to the earth.
testlamp - connect the clip on the lead to the wire and and the the probe to +12v, if it lights up the wire is shorted to earth.