electrical help - fan, horn, blinkers, temp

[wbute]

As far as I am aware the oil pressure sender wire is an earth. The amount of pressure increases the resistance of the earth which makes the gauge work. So it should never be live. The sender is probably no good if the gauge isn't working.
Go back to basics. Take out the globes in the tail lights. Use you test light to check if there is power there when it's in reverse with the ignition on.

[Vombil]

As far as I am aware the oil pressure sender wire is an earth. The amount of pressure increases the resistance of the earth which makes the gauge work. So it should never be live. The sender is probably no good if the gauge isn't working.
Go back to basics. Take out the globes in the tail lights. Use you test light to check if there is power there when it's in reverse with the ignition on.

ive checked tail lights. no power to reverse but tails and brakes are fine. globes also tested.
perhaps there is an oil sender on engine rather than a switch.
so frustrating! I will buy the test light this arvo