im hooking up a a/f ratio gauge and im in need of some help.... theres 4 wires, 2 white, black, gray. the 2 white are heaters and whats teh black for and the gray for... i would ammume that the blacks the ground and the grays the sinal wire but i dont want to so please let me know if u know...

 

black is ground and gray is signal. I asked the senior master ford technician that I work with so rest assured that this is correct.

 

ty... so what would i hook the positive up to? i dont want my gauge on all the time...

 

hey please help i got my car on ramps waiting to hook up the last wire... the positive

 

I'd put the positive wire on the instrument cluster fuse in the inside fuse box. that way the gauge would only come on when the car is started.