Help With Af Guage

[r_speedfreak_r]

hey all

just wondering if anyone had any enligtenment on fitting an air fuel ratio guage to there r33 skyline. Mine has a 3 wire oxygen sensor and using resistance checks ive found the power and earth so ive hooked up the guage to the remaining wire that goes to the ecu but the guage doesnt register anything. has anyone else had this problem?

One possiblity i just thought of was i have wired up the guage to the oxygen sensor on the dump pipe. do the guages have to be wired up to an oxygen sensor further down the exhuast after the cat?

your input would be greatly appreciated

[RANDY]

I can tell you definately that the sensor further down, in the cat is the heat-sensor, which lights up on your dash if it gets too hot.

Otherwise, where did you get power and earth from?

You should get power from an ignition wire, so it's on when the car is on, and ground from the chassis (a clean spot).

Make sure you have that right first... most of those displays will light up without it connected to the ECU wire. (on fully lean)

Once the power is 100%, then yeah, i'm pretty sure you want the single sensor wire that goes to the ECU. Mine has two black ones, which are for the heater part of the sensor, and the third is the voltage/signal wire.

[r_speedfreak_r]

i think ive confused you a little. the guage is a three wire being a power earth and sensor wire. i've got the power and earth setup on the guage it lights up and everything. the oxygen sensor itself is also a 3 wire and according to the instruction manual that came with the guage it says on 3 wire oxygen sensors power is delivered through one and grounded on a second wire with the third wire being a sensor wire to the ecu. when i unpluged the oxygen sensor i found two terminals were connected so it must of been the power and earth terminals leaving the remaining terminal to theoretically be connected to the ecu which is the one i taped into. so as far as i know i'ts all been wired up correctly but i dont think theres enough voltage being passed through the sensor wire for the guage to register a reading

[Craved]

did you use the centre wire in the loom to the O2 sensor?

Edited July 5, 2006 by Craved

[RANDY]

No no, I understood you. =-]

But i'll try and make myself a bit clearer... The wire that you used on the 02 sensor... i don't think there is a positive and negative on it. The two same-coloured wires (white? or black? can't remember) are for the heater element in the sensor. This leaves one wire of a different colour to the other two.... that is your sensor wire. I'm suggesting that you check that you have tapped into that uniquely-coloured wire for the guage.

The sensors range from 0 to 1 volt, so if it's hooked up correctly and you still get nothing, then get a multimeter onto that sensor wire and make sure your sensor is actually working. =-]