Your car has dozens of computers that will be damaged by reverse polarity. To avoid that, they always have diodes built in. Diodes are one-way valves for electrical current flow. They are put in the computers backward between the 12-volt feed and ground terminals, so under normal conditions it's like they aren't even there. When you mix up the battery cables or jumper cables, the diodes become "forward biased", meaning they act like a short circuit. That is intentional and causes the fuse to blow, thereby protecting the rest of the computer.
You can be sure there are going to be multiple blown fuses. There will be a fuse box under the hood, and there should be one inside the car. Pulling each fuse out to do a visual inspection is very time-consuming. If you have a test light, the spade-type fuses have two test points on top that make the job go very quickly. Turn on the systems that are not working, then check for 12 volts on all of those fuses. If you find 12 volts on both test points, that fuse is good. If you find 0 volts on both sides, that circuit is turned off. You are looking for any fuse that has 12 volts on one test point and 0 volts on the other one. That fuse is blown.
Many older cars used fuse link wires spliced into the wiring harness. Those take some time to burn open, and usually will not do so from reverse polarity. Fuse link wires protect large circuits that feed multiple smaller circuits. It's the fuses in those smaller circuits that will blow and stop current flow.
Sunday, May 7th, 2017 AT 4:37 PM