Ok for some reason im drawing a huge blank tonight and im helping a friend hook up an a/f gauge and i need to know which wire i could hook the power wire from the gauge to so it will work when the car is turned on..I know this is a stupid question and ive helped my other friends do this **** all the time but for some reason i cant remember and its too late to call any of them...thanks for the help. btw its a 94 civic dx.

 

steady power when car is on?? id say hook it to the interior fuse box on something that comes and stays on when car is running like the fuel pump or something.
the o2 sensor does not recieve a steady stream of 12v power. it flucuates as needed.

 

accesory plug (cigarette lighter) is switched(only when car is on) 12v power. It what i use for my gauges.

 

dont use the fuel pump wires thats ust asking for problems.... use the wires for the stereo.... or cigarette lighter.... something small and insignificant like that ... dont want to risk shorting something out major liek the fuel pump ... cuz thats a pretty penny

good luck man