I have an 89 5.7 TPI -

I think the O2 input to the ECU is a solid purple wire, grey connector (marked "D") pin 7. Does this sound correct? If I splice in an O2 signal right at this wire should it work, or is there something else in that circuit?

I can't get a reading in the ECU from the O2 and I am suspecting a wiring issue -

thanks in advance

 

From my 89 service manual....
Ppl wire , o2 sensor signal D7 .
Tan wire , o2 sensor ground D6
And I dont think there is something else in that circuit.

 

Thanks - bear with me if this is a stupid question - but the tan D6 O2 ground - where should I put this for testing purposes? Neg battery? Chassis?

thanks - been tracking down no O2 signal in ECU for too long to mention!

 

I cut the tan wire and attached it to the body and instantly saw the O2 swinging - thanks for the help

 

Good news The tan wire from the ecm is attached to the ground strap Rear of RH cylinder head . Maybe want to check that ground not being lose or bad connection causing some other issues in the future ...