I bought it used...there are three wires, black, red and purple...this is for a 94 Z28...any guides please? thanks guys!

 

black-ground, red-ignition,purple-sensor..

hope that helps..

 

Sorta....

Red - igniton? What wire do I splice into exactly? I thought the red one maybe spliced into something like the headlights so it lights up at night...maybe Im way off (prob am)

Purple - What 02 sensor wire, theres 4 of them?

 

You don't want to splice into the sensor wire itself. Splice into the harness wire, or at the PCM connector. The O2 sensor wires are on pins C8 and C20, and one is purple, and one is purple/white. Can't remember which is left and right. You can run both of them to a single pole-double throw switch, and be able to read either the left or right sensor.

The best place to get "switched" +12V power is from the fuse panel at the end of the dash. There is a space marked "IGN" with a single spade lug in it. That is swithced +12V power, and the circuit is protected by the fuse right above it.

If the gauge has a light, typically the light is wired independant of the +12V for the gauge electronics, as is the ground. The best source of power for the light is finding the wire on the headlight switch that provides the power to the lights. That way, your gauge only lights up when the lights are on. You can also use the wire coming out of the dash panel light dimmer rheostat, if you want the light on with the headlights and "dimmable".

Are you sure you want this gauge? I really don't think they provide much in the way of useful info.

 

I picked it up with the pod for $48 shipped...I figured it wasnt a bad deal... I didnt know they didnt do much? Figured it would tell me at least if Im runnin too rich or too lean till I can get it dyno tuned... Thanks for the info! Does it matter if I splice into one or the other for the purple wire? Do I really need a DPDT switch? And Im really not sure if it is backlit or not...just figured the red wire was for light, but ignition does make sense, needs power from somewhere. thanks again guys!! I'll try to screw this up, err I mean install it Sunday hehe

 

ok, should of been more specific..

for the sensor if you don't mind spending more $ you can go to ls1speed.com and they have a harness that is plug and play to hook up an o2 gauge.. you don't have to splice your sensor lines.. that is what I am using..

for the ignition.. any switched source that is on when the key is on is fine...

It is not backlit.. I have had two over the life of the car, one was cyberdyne.. the current one autometer.. the lighting is provided by the leds themselves.. I guess they thought that was good enough..

 

how does that thing on ls1speed.com work? BTW, i have an a/f gauge that does not light up when i turn the key to "ON" but at night when i turn the key to "ON" it does light up. what is going on!

 

hey i dont mean to hi-jack your post at all, but is there any DIY online manuals to install different gauges, i just got a wide array of them for the new motor and im very picky on who does the wiring in my car i solder everything, heat shrink, etc im just very picky and dont like fires due to someone cheapin out an doin a half assed job ya kno? i was hopin fred would know

 

i have the air/fuel...autometer...digital one.... basically all its good for is a lightshow... for some reason it just likes to dance around but on a cool night it actually does seem to read right... aka when i step on gas it goes green and as i back off it it slowly fades to yellow..and at stop red...i dont know...95% of time it just looks cool

 

You might think the A/F gauge doesn't do much until your O2's aren't working right then you will notice it starts going into green quite a bit and if it's in the green a lot you will be fouling plugs. You don't think they do much, But watch it when your car starts running rich or way lean, In my opinion it's better to have one than not unless you have an EGT gauge hooked up.

 

in a sense yes, but there are sensor lights you could wire to tell if ur O2s are goin bad, the a/f gauge does do a good job of that but is no where near accurate but you will notice when ur O2s are shot =) mine were already then i put the gauge in an viola MPGs went up an all

 

What brand of gauge is it?

The harness from ls1 speed just plugs into your o2 sensor and has an extra line spliced into it to wire to the sensor line of your gauge.. it is just a jumper with factory connections on either end..

 

its an autometer. but it used to light up when i turned the key to "ON" (not turn the car on) and now it doesnt, whats goin on?

 

HAHA, ok thank God cuz I just installed it and it looks like the knight rider back and forth, lol. I did install the SPDT for both the right and left bank which is handy Well for the most part it's reading back and forth between the yellow and red and under WOT it's green. Hope all is well...

 

That is the same one I have...

mine lights up one led when the ignition is turned on, and when the car is started does its little dance.. Since yours is not lighting up I would say it is not connected to the power or ground properly, though if you don't have all wires hooked up all bets are off.. hook everything up, run the car, and then if it doesn't work trouble shoot..