Thread: NEED HELP WITH OIL PRESSURE SWITCH

Electrics aren't my field

I would start by checking the switch using a multimeter, switch is open when engine is stopped and closes when engine is running (oil pressure ok). If ok go to next stage.

Now you said it is operating opposite to what it should, by this I assume oil pressure lamp is off when ignition is on but engine stopped, then illuminates when engine is running.

That tells me the lamp is ok, so the next device I would check is the relay for the reversing light.

The reversing light should only come on when reverse gear is selected and the engine is running, i.e. oil pressure switch is closed.

If the revering light works correctly, the relay would seem to be ok and the plot thickens.

Forget that oil pressure switch - its arse about compared to normal switches and requires relays etc to make the light work properly.
Fit a normal switch that closes when it has no pressure - about $10-15 from any auto shop. Either disconnect the wires on the old one and leave it where it is, or remove it and connect your new switch there

If you leave it there, there should be another small blank in the main oil gallery on the RH side of the block. Same level as the existing switch but forward - sort of behind the oil filter.

I'm using a Tridon P/N TPS007 switch that I got from Bursons, but it might have an adapter to match the thread in the block - I can't recall without looking at it.

Steve

Would it be easier to have the switch normally open or normally closed?

Originally Posted by flagg

Would it be easier to have the switch normally open or normally closed?

If its in series with the light (easiest way to do it), then normally closed.
No pressure == closed == circuit made and light illuminated.

Steve.

I'm guessing the County wiring is much the same as my Stage 1. Only Land Rover could have thought up the oil pressure switch wiring. Here is my simplified version of what happens. Probably the reason it is linked to the reverse lighting is that you don't flatten the battery if you leave the car in reverse without the engine running. Any other ideas?





Cheers
Pete

Originally Posted by captainslow

I'm guessing the County wiring is much the same as my Stage 1. Only Land Rover could have thought up the oil pressure switch wiring. Here is my simplified version of what happens. Probably the reason it is linked to the reverse lighting is that you don't flatten the battery if you leave the car in reverse without the engine running. Any other ideas?





Cheers
Pete

The reason for linking it with the reverse light is Australian Design Rules don't allow the reverse light to illuminate if the engine is not running and transmission not in reverse.

I suspect the reasoning is to do with other motorists behind the vehicle with its reverse light illuminated.

i did a converstion on mine at the momant when theres oil pressure the light is on but first thing before i start its off
but i had a look at our 120 diesel and the one i use for the conversion and they have a relay that the oil prusser switch runs to would i have to run that too ???

Thanks
Tom

The oil pressure switch and relay are required for the reversing light to operate correctly (ADR rules) - see the posts above and the wiring diagram in the files section.