Help! Relay Wiring Issue (Wideband O2)

[nullrout]

Greetings all!

I am wiring up an NGK AFX Powerdex Wideband O2 Sensor and am having issues with powering it with a relay.

I bought a 12VDC relay and a 5 wire wiring harness to ease connection (yeah right like any thing goes easy for me).

Terminal 87 wired to a ground point on the passenger side fender under hood.

Terminal 86 wired to power for the AFX

Terminal 85 wired to battery via 20A fuse

Terminal 30 wired to switched port (IGN) in the fuseblock

With this wiring here are the voltages I get with the ignition switch turned on:

From pos on battery to 87 ---- 12.5V
From neg on battery to 85 ---- 12.5V
From neg on battery to 30 ---- 12.1V

All expected right?

Now here is the kicker:

From neg on battery to 86 ---- 9.0V!!!!!

I tried three different new relays and pulled a known good from my fan wiring and all four relays have the exact same 9ish volts on output from the relay. Do I have something wired wrong? The only thing I can think it could be at this point in time is the harness itself...what do you think I should try?

 

[RmvBfrFlght]

Try this:

86, ignition switched power to operate relay, use an accessory tap for it to power off while cranking
85, ground
30, fused battery power
87, to AFX power

RemoveBeforeFlight

 

[nullrout]

I just came back to post that I found the problem and RmvBfrFlght got it first...I printed the first diagram I found for "12V relay wiring" web search...and it was wrong. I found 4 or 5 other diagrams that have it listed as above.

Thanks for the reply!

AFX is warming up for calibration as we speak!