Which wire does the A/F gauge need to be spliced

**SpectorV** · **Which wire does the A/F gauge need to be spliced**

I know it goes on the o2 sensor but which wire on an 99 up mustang?

97Stallion · 08-03-2004, 12:31 PM

I believe it's the same as 94-98 Mustangs, but I believe it was a gray/red or a black/red wire

Monkey · 08-03-2004, 12:32 PM

I'm not quite sure, but one is gonna be a ground so figure out which that is and don't use that for a splice.

Anyway, unless the A/F guage is wideband, you will not get accurate readings and it will be mostly a waste of money. If it is the Autometer A/F lighted guage, then it is even more money wasted.. That is a narrowband guage and will tell you you're too lean as your engine is blowing up... not their best product.

**SpectorV** · 08-03-2004, 03:26 PM

lol yea its not my cars its a guy i know he watns me to help him put a a/f gauge in his car. so red/black, i can see which wires are hot to figure out the ground but .... will there only be one hot wire? will it mess up the gauge if i stick it on the wrong wire? i have read two posts that have said red/gray or red/black wire is the signal/power wire? is it the signal or the power wire i need to splice into.

97Stallion · 08-03-2004, 03:41 PM

Yeah it has to be the right wire or it could screw up the gauge. Let me look when i get home and I'll post it. But the more I think about it, there are 4 wires, I think one is white, one is black and the other two are grey. Just let me get home in about an hour or so.

**SpectorV** · 08-03-2004, 06:16 PM

alright, if you get this before you do, i hope you do lol, the guy aint getting us to help him tonight, i think he is gonna get some diff gauges.... but either way we need to know on this forum, no one else does....

97Stallion · 08-03-2004, 06:47 PM

D'oh!! Well I completely lost my memory, but I know for a fact it's either red/black or yellow/blue now. let me do some more investigating

97Stallion · 08-03-2004, 06:53 PM

OK, well I'm like 95%, not 100% that's is the red/black because the yellow/blue has the heating element so I'm going to assume that wire goes to the computer to let it know the temp of the O2 sensors and the red/black one actually relays the signal. I hope this work for you. If you want me to be 100% sure you'll have to wait till saturday when I have time to jack up the car.

97Stallion · 08-17-2004, 12:07 PM

I just wanted to restate that I finally got a chance to check the wire I attached my A/F ratio gauge to was indeed a red/black wire, so now I'm 100% positive of this.

Danger Dude · 08-17-2004, 12:38 PM

by the way where are these wires located at will also help people install the products

**SpectorV** · 08-17-2004, 02:23 PM

good info we need to sticky this somewhere about the basic install of each type of gauge its very hard to get info on an a/f gauge as you have seen lol thanks for checking though now we know.

97Stallion · 08-17-2004, 02:27 PM

For those who do not know, the red/black wire is located before the driver's side front 02 sensor connector.

steedav6builder · 08-17-2004, 05:15 PM

i wanted to get an autometer a/f guage too. is it true that they are not acurate?

97Stallion · 08-17-2004, 05:21 PM


Quote: Originally Posted by steedav6builder i wanted to get an autometer a/f guage too. is it true that they are not acurate?

i would have to say that's like 60% true. Is it going to come straight out and say your A/F ratio is 12.7:1 or something like that, no. But if you learn how to read it correctly, it'll give you more or less an approximate reading. If you're looking for something that gives you an exact number, then you'll need a wideband 02 sensor which usually costs around $400.

**SpectorV** · 08-17-2004, 09:08 PM

i have heard they are mainly a light show that when you are so lean you have a problem the gauge will start to read lean, and by then its to late.

97Stallion · 08-18-2004, 06:01 AM

That mainly pertains to blown engines. Because they have to run a little richer in order to be in the "safe zone" on a N/A car, you can run pretty lean and still be ok. On a SC engine anything about 13.5 and you're pressing your luck as to on a N/A engine you can do about 14.5.

jimmy_beaner · 08-23-2004, 02:12 PM

ok, what's this gauge good for?... like if you had to say, these are three extra gauges you should have, for a non-supercharged car, just with basic mods.... like dual exhaust, and CAI.... and P&P coming next summer... what 3 gauges (I want to get the gauge cluster pillar that runs up the door....) would you say I should get?