So I was off on another problem this evening, and bridged leads A & B and my cooling fan immediately came on. Turns out that it always comes on when I insert the paperclip, and turns off when I remove it. What did the guy before me do with this fan??

absolutely nothing. Its supposed to do that. It was made like that from the factory to indicate its in diagnostic mode...

Ahhh, okay... I feel like an idiot. Live and learn I guess, thx.

The fan never came on when checking codes on either of my Camaro's - strange - they were both RS's with single fans.

maybe some cars are different? But its normal for my dual-fanned TPI...