heated O2 sensor circuit question

[Mike Brown]

Ed wrote:
> 
> I plan on relocating my O2 sensor further down into the header since the
> original spot reads off only 2 of the 4 cylinders. Thing is, the
> original sensor is a single wire, and I think I'd need a heated one for
> the new location.
> Any idea how to wire the heater circuit? Is it safe to wire the circuit
> to a switched (engine on) power source or was the heaer designed to shut
> off once it reaches operating temp?
> 
> -Ed

Ed,
	On my Edelbrock/Webber ProFlow the heated sensor is powered off the
same circuit as the fuel pump.  I think that was done only for wiring
harness convenience.  I see no reason why it couldn't be powered thru
the ignition switch.  I believe it is a Bosch unit from a Ford.  Three
wires, +12v, ground, O2 sensor output.

Mike