Electricity has always been a bit closer to magic than science for me so hopefully this will be an easy question to answer (and hopefully for me to understand!).
I just made a home for my new Puma 3cfm compressor in the back of the van in the little cubbyhole under the rear closet (50 layout). I have it rigged up with alligator clips so I can pull it out and run it off of the battery or another vehicle, but it's heavy and I'm thinking of hard wiring it in.
This is how I'm thinking it should go, please correct me if I'm wrong:
Positive off of the compressor to suitable fuse in 12v fuse box.
Ok so far? If so, I'm assuming I can ground the negative wire to a bolt right next to the compressor that ties the closet/bed unit to the frame? Or does he negative have to rout back to the fuse box as well?
While looking at the fuse box I realized I may have been living with a false understanding of how 12v wiring works... Looking at the battery and seeing the positive and negative cables coming off, I've always thought of the electrical system in a car as a closed loop, like the circulatory system. Electricity flows out of the battery, throughout the vehicles starter, radio, etc and back to the battery.
That's how it looked to the eight year old me and I've been interpreting all of my automotive electrical knowledge off of that assumption ever since...
I've replaced plenty of batteries over the years, but never followed that negative wire to see where it goes. Don't tell me it grounds straight to the frame 18 inches away?
Thanks for any illumination you can offer. Very happy with the self sufficiency we're going to have being able to air up on the spot...
-Mark...