Big Blue's Transformation

[Gary Lewis]

Calibrating the O2 sensor was interesting. You put power to the meter with no sensor connected and it'll show E2. Then you power off, connect the sensor with it laying in free air, and power back on. It'll go through its calibration routine and then indicate 22.4:1 AFR, which means it is calibrated.

But getting power to the meter requires either starting the engine, pulling in the relay another way, or removing the relay and jumping across it. I opted to pull in the relay by disconnecting the W/Bk stator wire at the connector between the alternator and the fender liner and applying 12v.

That let me calibrate the sensor and then I installed it. Started the truck up and found that the AFR meter works but the "stock" voltmeter, meaning the one in the gauge cluster that Rocketman modified, doesn't. So obviously the relay is getting pulled in by the stator circuit but the signal isn't getting to the voltmeter.

I'm guessing that's because I didn't get the connector clicked into the gauge cluster all the way - power and ground to the voltmeter are on the very end of the connector. And while it is a huge pain to take the cluster out, I may be able to get to it by taking the dash pad/cover off. At least that's what it looks like when checking out the spare dash I have in the attic. So I'll give that a try tomorrow.

But back the AFR meter, it rebooted several times when I blipped the throttle. That indicates that maybe the RPM dropped so low that the output of the stator wire is letting the relay drop out. I checked that relay and on straight DC it dropped out at 5.15 volts, but I found another that drops out at 4.75 volts. I put that in and the few blips I did didn't cause the meter to drop out. But we will take the truck on an outing in a bit and I'll find out then.

And the tach works great! Very smooth and the idle is more accurate. Thanks again, David!

Minor update. I posted this in WHYDTYTT. Added the rubber trim to the behind the doors, on the cab corners.