Cycleterminal.com has connectors and tools for crimping. So does easternbeaver.com, but shipping is prohibitive unless you are buying about $100 worth of stuff from them. You can probably salvage the old connector with the appropriate tool (or a long needle) to depress the little finger that holds the spade in the plastic housing. If the remaining wire is too short, you will have to splice in a piece for each conductor using heat shrink tubing and crimp type butt splices. I'd stay away from the butt splices that are self soldering with the application of heat - I read some really bad (but descriptive) evaluations on Amazon. If you must use these, got to a real auto store (around here Napa is good, O'reilly's and Autozone not as good, imo). Then crimp on new spades (male or female) to the new wire and insert them into the plastic housing.
I'm assuming a fuse did not blow...but if it did, replace it after you make the repairs.