Sorry, Eddy, I should have mentioned that earlier.

Its a OBD I 93 Auto 4x4 6G72 3.0L V6. So it required the (+) to Pin 1, and (-) to Pin 12. As seen here:



I got it start up again and drove it around the block to recharge the battery since I haven't driven it and I didn't want to drain the battery in the process.

So as I was trying to maintain a steady grip on the prongs to grab the codes--its tricky holding the proper position/stance--with the analog voltmeter but I abruptly realized I didn't know the settings to properly read them so I tried to do a quick search (to no avail) and just decided on 9V as that got the best reading on a AA battery... so when I went back to grab the codes the same issue occurred: the check engine light won't turn on.

It won't go into self-check and the voltmeter is no longer picking up any activity.

Edit: Ok a few hours later and the Check Engine Light still won't appear, and I unplugged the battery with no luck either. And as expected no activity monitored from the diagnostic pins.