oil pressure snedint unit

[braganjackson11]

i need some help getting the oil pressure sending unit hooked up properly. As it is, the green oil pressure light flickers on and off when i don't have my foot on the accelerator and i don't even have the oil pressure guage hooked up. any explanation of what terminals go where would be appreciated.

[pickuprover]

There is supposed to be a white/brown wire that goes from the oil pressure switch (located on the top of the oil filter housing) to the oil pressure lamp on the dash. If it is flickering, I would assume that the end that is supposed to be on the pressure switch is loose somewhere in the engine compartment and is grounding out to the engine, causing the light to come on preiodically. I hope that your wiring harness is ok, after all the work you put into it.....

[TerryS]

The first, and most obvious thing I would check is that you have enough oil pressure at idle. The pressure switch, in the absence of oil pressure, makes a contact, to ground, to illuminate the light on your instrument cluster. It takes about 5 psi to open the contact. If the light is flickering at idle, you may have very little oil pressure. You should unscrew the pressure switch and screw in a mechanical oil pressure gage to confirm what you actually have for pressure. If it's 15-20 psi hot, then suspect the actual switch, as they do occassionally weaken to the point that it will make a ground path even when sufficient pressure is there.

[braganjackson11]

thanks for the help, we'll definately have to check on the actual pressure...where can we get one? a local autoparts store?

there's three different terminals on the sending unit it self, one on the little end and 2 right next to each other on the other big end, how are all these hooked up?

[pickuprover]

Originally Posted by braganjackson11

thanks for the help, we'll definately have to check on the actual pressure...where can we get one? a local autoparts store?

there's three different terminals on the sending unit it self, one on the little end and 2 right next to each other on the other big end, how are all these hooked up?

Mine only has one terminal on it.... someone must have replaced it with an aftermarket one at some point (or someone has changed mine to a single terminal one, but the parts manual looks like it shows a single pole, so I cannot advise you on this) But there must be a way of testing with a ohm meter which one goes from ground to nothing as the pressure builds.... or there is always the option of calling RN or your prefered parts supplier and see if they have the same one as you instick, and which terminal you need to use.....

[pickuprover]

Oh, post a picture of it, and will ask around as to which pole is which if you would like....

[TerryS]

Originally Posted by braganjackson11

thanks for the help, we'll definately have to check on the actual pressure...where can we get one? a local autoparts store?

there's three different terminals on the sending unit it self, one on the little end and 2 right next to each other on the other big end, how are all these hooked up?

You aren't likely to find it at your local autoparts store, as the threads are British Pipe. You can find a mechanical oil pressure gage but be sure it has the British Pipe thread adapter.

You're really confusing me with your description "big end" "little end" There's the end with the terminals, and the other end is threaded. It sounds like you are describing the whole piping piece and two senders, as used on trucks that had the electric oil pressure gage, one of the senders may have looked like it had two spade connectors , but it's really just two terminals, common connected, like a little piece, bent in a 'U' shape.
There are oil pressure gage senders that have an internal switch of an idiot light or alarm, they have multiple connections.
Like somebody said, post a pic.

[braganjackson11]

haha sorry for the confusion i'll post a pic when i get home from school

[onslow]

Originally Posted by pickuprover

Mine only has one terminal on it.... someone must have replaced it with an aftermarket one at some point (or someone has changed mine to a single terminal one, but the parts manual looks like it shows a single pole, so I cannot advise you on this) But there must be a way of testing with a ohm meter which one goes from ground to nothing as the pressure builds.... or there is always the option of calling RN or your prefered parts supplier and see if they have the same one as you instick, and which terminal you need to use.....

The correct o/p switch on a 2.25 has only 1 terminal and is the same as the 3.5 v8 one too its a standard lucas part

[braganjackson11]

here is a picture of the oil pressure sending unit that came on ours when we got it.

the green and yellow wire goes to the green oil pressure light in the speedo, the red wire goes to a power terminal from the fuse box, and the black we have going to the oil pressure guage. the guage has two terminals and i can't remember what the other one is hooked up to at the moment, i'll look when we replace the headlight switch tomorow afternoon.

[pickuprover]

Is that a spin on adapter I see... I still have to get around to getting one of those, but then I would miss the oil down the shirt sleeve...

[braganjackson11]

yes it is a spin on

[onslow]

Originally Posted by braganjackson11

yes it is a spin on

Generally the o/p switches are reliable wat is the pressure gauge reading when the light is flickering also check the green wire isnt earthing its self somewhere remove the wire when its idling and check its not still flickering

[braganjackson11]

the guage doesn't read anything, it stays at zero

[TerryS]

Your oil pressure sending unit is not wired correctly.
There should be NO + wire going to it. There should be a switch + wire going to the guage, then from the guage to ONE (either one, they are the same)of the terminals on the sending unit. Those two pins are a common connection. If You haven't managed to blow the fuse which feeds that red wire, then you've likely burned out the sending unit.