Wiring Up A Super Bright Led To My Oil Press Gauge?

[Simon-S14]

Basically i have a oil press gauge, an electric type which has a single wire sender unit, measuring resistance as the pressure increase, is it possible to wire up a super bright LED to come on when there is zero or close to zero oil pressure?

I dont always look at the gauge on the track, it would be nice to have a bright light that i can see no mater what and shut it off before major damage happens.

Im thinking it cant be too hard, since i just work out the resistance of the sender unit with motor off, and some how make a circuit to match that. anyone want to run through an idea with me?

EDIT: stock gauge isnt hooked up and neither is the light, both are dodgy as on the 32, i have an after market gauge which works a treat, just want a fail safe.

Edited February 25, 2008 by Simon-R32

[R34GTFOUR]

you can get oil pressure switches, (only lights up with no oil pressure), so it wouldnt be hard to t-piece into the oil pressure sensor and have the switch running off that. Then just have that running straight to the led which you would have a igntion power feed to it since the oil pressure switch will work off a negative. Should cost you less than 20bucks for the switch, t-piece and led, cheap insurance i say.

I'm going to hook something up very simular but maybe to a buzzer when my car starts making a tad more power

[Simon-S14]

already have a t piece with the sender unit and a temp probe for two gauges... so makes it a bit harder as i dont want 2 sets of T pieces.

is there a way of doing it going by the high and low resitance readings from the sender?

[GeeTR]

Hobbs switch set to close circuit at 10psi or less. Slap some resistors onto a clear, super bright red 10mm LED. Booya - easy.

Edited February 25, 2008 by GeeTR

[GeeTR]

U could use the sender with a variable resistance/voltage switch from Jaycar or something, but a simple oil pressure on off switch like R34GTFOUR's saying, would be more reliable, less parts and cheaper.

[**RB2530**]

From the point of view of reliability, a seperate pressure switch would get my vote. ie if one of the sensors fails you have a backup that is still working..I am going to do the same thing...Just trying to find a switch with the right pressure switching point...

The only issue is running two t-pieces. I run the VVT oil feed line through a t-piece as well so I would have 3. The assembly will get quite long which is bad because you increase the mechanical stress on the fitting that screws into the engine...Not a good thing if that breaks...however your gauge and light / buzzer will come on straight away if it does...You could get tricky and wire the pressure switch into the ignition so it cuts the engine. The only trouble is you would never get your engine started because you dont get decent oil pressure at cranking speed. To fix this you need a timer that ignores the switch for a few seconds...more complications and not worth worrying about. You may do other damage as well if it shutsdown at the wrong time.....ie WOT 7000rpm

My plans are to make up a 1/8" bsp manifold (1 inlet and 3-4 outlets) and mount it somewhere on the block or on the firewall feed by some good hose...