A/F ratio guage installation`

[02 Vortech]

hey guys i got my autometer a/f ratio guage mounted but i dont know about the wiring. Could someone please help me with this. The black one is supposed to go to a battery ground, but there are 3 black wires comming off the negative side. Then w/ the red ignition wire. Where do i solder it to. do i just solder it the red ignition wire comming off the steering column? The the violet 02 sensor wire. Where do i mount it to on the 02 sensor wire. here are 3 wires comming out of the 02 sensor, then it goes into a plastic thing then into another set of wires. Please help me here.

[Sparky2263]

The O2 sensor heater (12V and ground) doesn't care which goes where. Just so long as you get the purple wire (sensor signal) right and the other 2 to 12V and ground. The heater draws about an amp so an 18 ga. wire or better would do the trick. Needs 12V ignition so make sure it's a switched source or it'll drain the battery.