Neil P
|
| posted on 11/7/10 at 03:04 PM |
|
|
Oil light opposites
I'm running a Toyota 4AGE in my car and using sierra gauges.
I've taken the wire from the pressure sensor and run it directly to the oil light input on the sierra clocks.
When I switch on, the oil light doesn't come on as you would expect but does when the engine is running. It flickers at tickover then lights
constantly above that.
Being something of an electrics numpty, I'm struggling to understand why. Has anyone got any ideas how to put this right, please?
Cheers
Neil
|
|
|
|
|
britishtrident
|
| posted on 11/7/10 at 03:08 PM |
|
|
It shouldn't flicker at idle ---either low oil pressure or idle speed way to low.
As for reversing the operation wire it through a change over relay.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
|
|
|
RazMan
|
| posted on 11/7/10 at 03:23 PM |
|
|
A relay on a sensor??? Sounds like the sensor is not right for the clocks or you have the signal and earth wires the wrong way round. Some sensors put
out a rising voltage for rising oil pressure, some have falling voltage for rising pressure.
Probably a good idea to get a Ford sensor and stick with that.
[Edited on 11-7-10 by RazMan]
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
|
|
|
britishtrident
|
| posted on 11/7/10 at 03:45 PM |
|
|
A lot of Japanese cars had an oil pressure switch that works this way it was wired to main relay to turn the fuel and spark off if the
engine wasn't running.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
|
|
|
Stott
|
| posted on 11/7/10 at 03:53 PM |
|
|
I though the single wire switches were short to earth below the set pressure, then open circuit above.
Your problem would indicate the switch is open circuit until the rated pressure is reached then it goes short to earth. You'd probably be best
replacing the switch for one with a known pressure value which shorts to earth when it's not pressurised. Or you'll end up having to put a
relay in to switch the light via the pressure switch's output.
You just want a single wire oil pressure switch, of the correct thread, which is rated at what you want such as one of these:
LINK
This would work with your standard ford clocks and oil light.
It almost sounds like you are trying to connect a pressure sender to an oil light rather than a guage.
Sender - guage
Switch - oil light
HTH
Stott
|
|
|
Stott
|
| posted on 11/7/10 at 03:56 PM |
|
|
quote:
Originally posted by britishtrident
A lot of Japanese cars had an oil pressure switch that works this way it was wired to main relay to turn the fuel and spark off if the
engine wasn't running.
That's a good idea but quite mad, how would it ever start though?!? My cars never achieve enough oil pressure while cranking to extinguish the
light, if that was the case the fuel and spark would never be on! 
|
|
|
britishtrident
|
| posted on 11/7/10 at 06:31 PM |
|
|
quote:
Originally posted by Stott
quote:
Originally posted by britishtrident
A lot of Japanese cars had an oil pressure switch that works this way it was wired to main relay to turn the fuel and spark off if the
engine wasn't running.
That's a good idea but quite mad, how would it ever start though?!? My cars never achieve enough oil pressure while cranking to extinguish the
light, if that was the case the fuel and spark would never be on!
Honda used this system also Rover used it on a lot of models the main relay is also energised while the starter is in operation on more recent models
the engine ECU powers the main engine relay for x seconds after the igntion is switched on or the starter is operated.
|
|
|
matt_gsxr
|
| posted on 11/7/10 at 07:34 PM |
|
|
So, from what I am reading.
Oil pressure high, switch closed
Oil pressure low, switch open
I think what you need is a pull-up resistor. Effectively if you wire the bulb across the switch, with a resistor (something l a 100Ohm with decent
power handling), then it will do the sort of things that you want. The only downside is that the bulb will not be quite as bright.
Alternatively relay, or transistors.
Matt
|
|
|
Neil P
|
| posted on 12/7/10 at 07:55 PM |
|
|
okay, cheers.
gives me some ideas of where to look.
Having looked on web for AW11 dash, it does have a pressure gauge, so that may be where my problem lies - pressure sender signal to the oil light.
Neil
|
|
|
