Oil pressure sender wire - should I reconnect after fitting guages?
 

Fitted Autometer gauges yesterday but I wasn't sure if I was to reconnect the OE pressure wire onto the Autometer sender. I wasn't sure if I should because as I've now fitted a different sender wouldn't it give a different reading to the OE wire?

If I do need to reconnect it why wouldn't the guage work off the OE wire. Seem to me this wire should be connected if its linked to the ECU or similiar but I've done a search on SN and can't find any mention of re-connecting the OE wire.

I did find that its OK for the gauge to read upto 100PSI on start up thne drop down to about a smidgen under 50. Seemed to me either the gauge was wrong or wouldn't read high enough for an Impreza. 100PSI seems high though.

Anyone?

I am suposed to be fitting my Autometer Gauges at the weekend, as far as the OEM sender wire, either fit a t-piece and run both the new sender and the old one or use the new one and tape the oem wire out of the way.
Question for you where did you pick the live feeds up from for both the switched live feed and lights live feed.

All I've done is move the OE wire out the way but where was this wire sending its information too? Although seems an idea to run both using a T no-one else seems to have done this and no warning lights appear now the wire is disconnected.

As for switched +ve I used the fag lighter and Lights +ve the fog light switch wire - purple and something IIRC.

http://stefanostadal.homedns.org/car_mods.htm - I used here.

Think if you talk to either lemans motorsport or possibly scoobymania they do the t-piece. I had the part number but as usual you collect a load of info and then lose it.
Isn't it a load of hassle to get at the cig lighter.

Not really, a few screws, remove gearknob, a good yank and its all free. I didn't remove my headunit just reach behind the dash and found said wire.

just leave the oem one unplugged, its not needed, and only warns when oil pressure is as low as 0.5 bar or something stupid.

pressures should range between 3 bar and 9 bar (44psi and 132psi) most times on cruise light load, it will be around 6bar (88psi).

I recently saw a psi gauage in a new wrx, and suggested they changed the gauge for one that read up to 150psi

[QUOTE=EddScott]Fitted Autometer gauges yesterday but I wasn't sure if I was to reconnect the OE pressure wire onto the Autometer sender. I wasn't sure if I should because as I've now fitted a different sender wouldn't it give a different reading to the OE wire?

If I do need to reconnect it why wouldn't the guage work off the OE wire. Seem to me this wire should be connected if its linked to the ECU or similiar but I've done a search on SN and can't find any mention of re-connecting the OE wire.

QUOTE]

If it's the same as other cars, the wire onto the pressure switch is an earth wire for the oil warning lamp, when the pressure drops below it's set point, the wire is shorted to earth and lights up your oil warning. So it's not a good idea to stick it on anything else :)

I have Defis on mine and the problem arises when you change the oil. The Defis don't register on engine cranking so having the oem on the other side of a tee would indicate when the oil pressure is up.