Hi everyone,

I want to hook up a heated oxygen sensor to my car and have found Vader's pics on how to do it. However on my 82 I don't think I have a evap purge solenoid so I thought about hooking into the air select solenoid valve signal from the ECM instead. My factory service manual tells me that when the ECM enters closed loop mode the ground is removed from this control line.

The emissions on my car has been largely removed so I don't know where on earth my air select solenoid valve would be, if it's still there at all, but I can hook into the line that leaves the ECM so that's cool. My guess is that the solenoid isn't there because I no longer have the cylinder exhaust ports for directing air into, and neither do I have a cat.

The real question is, how much current would the solenoid valve draw compared to the current draw of a heating element inside an oxygen sensor? If it's about the same, then I guess I could use Vader's diagram but not have to worry about using a relay to control the heating element since I'd be swapping one for the other, thereby keeping the electronics simple. The factory diagram shows no indication of a relay controling the solenoid valve.

Can I get away with not using a relay?

 

Anyone have any idea?

 

Vader's relay wiring diagram is just one option on how to wire the heated O2 sensors.

On mine I just spliced into a "hot when key is on" wire and connected that to one of the same colored wires and took the other one to ground. Works fine, lasts a long time.... YMMV of course

 

Thanks for that. I was just going for a more energy efficient method of going about it. Plus, I like wiring gadgets up to the car.