12v electric ratchet + custom 12v test harness!
 

So the other day, I picked up a new 12v electric ratchet from Harbor Freight, with a coupon of course. I'm pretty impressed with it, and it will make a handy addition to my tool bag when visiting the Pull-a-Part... but then I started thinking... it has a 12 volt battery pack...

https://cimg5.ibsrv.net/gimg/www.for...e8e79bfa9c.jpg
Alligator clips soldered/heat-shrinked to the pocket clips off a couple of ink pens.
https://cimg6.ibsrv.net/gimg/www.for...4c26035bdc.jpg
Test harness connected to the 12-volt battery, powering a bulb for an instrument cluster.
https://cimg7.ibsrv.net/gimg/www.for...51ec3a7ef0.jpg
Battery installed in the ratchet.
https://cimg8.ibsrv.net/gimg/www.for...7e026c519b.jpg
Close-up of the "harness" that connects to the battery.

I can use this to test basic 12-volt circuits at the Pull-a-Part (especially odometers!) and when I need to speed things up with the electric ratchet, I have that as well.