Ok here is my problem, I bought a car and it came with a autometer A/F Gauge and it wasnt hooked up, So I went ahead today and Hooked it up
Black wire was grounded to a clean spot on the chassis
Red wire was wired to Switch
Purple went straight to the White wire on the O2 sensor
Here is what it does, I turn the car on it does even light up,
I wait til it warms up and then when I Get on the gas it, The third Light from the lean would light up and then as rpm come back down the second Light from the lean side comes on and then the whole gauge turns off.
What is wrong, is it the gauge, I did try it straight from the battery to the o2 sensor and it did the same thing.

 

Hmm. Maybe it wasnt hooked up because it wasnt working properly to begin with.
Other than that, check on the white wire. Hook up a voltmeter to the same wire and it should fluctuate between .9 and .1 volts.
I am having a weird problem with mine too. When I turn on my headlights more of the led's on the gauge lite up. Thats just because of how the wire is ran though---too close to an illumination wire and its conducting power into the purple on the autometer a/f

 

You have it hooked to a 12V ignition source, right? If so, then I'd check the connection on the RED wire that you have it tapped on from the ignition source and the O2 sensor, for that fact. Since the wires are so thin(from the gauge), I had to double wrap the wire onto a standard wire tap(whatever you call it) Mine would go in and out cause it wasn't tapped properly.

 

check your o2 sensor.it will read lean when it is bad.

 

Any other ways of check this out.

 

When your RPM drops rapidly the gauge goes off because your setting goes too lean for the gauge. As long as the gauge is on at other times then it sounds like it is working.

 

also, when you leave the signal unhooked it should show full rich (+ and - connected only). if not, something is wrong with connections or the gauge.

hth, -C

 

lol, mine's just the opposite, when I turn my lights on, my A/F gauge reads like 3-4 LED's leaner than when off. Guess the power drain is affecting the reading, just one more reason why I hate this gauge..

which 12v power source did you guys use on yours? Maybe I just need to find a better power source cause I think i'm usuing the think red wire running near the fuse panel which could be overloaded, affecting the reading.

 

My gauge is wierd like that. It works somewhat normal in the day time..but still reads very lean. At night time it only lights up the last few leds on the lean side. But like i said in the day more normal..but still pretty lean.

And it is night and day like that. I was driving from san diego to oregon, in the day it read lean/normal but at night only the three of the lean led was lid...as morning came around (drove all night)..it started reading a little more rich again (but still lean). I think the gauge is a big pos if you ask me. Im going to barrow a friends and see if it reads the same way. I just think my gauge is broke personally. My EGT readings never changed.

liam