No electrical power to anything - even dome light.

Bad fusible link

You talking ecm bat fuse 20 amp? Voltage to that fuse is hot all the time. It comes from fusible link. Make sure battery has a full charge and connections all good. Then check fusible links, one way to check fusible links, use a test light and check voltage on both sides. I usually follow battery + circuits to find fusible links.

bad battery, bad battery terminals , bad ground wire , blown fusible links , blown ING fuse

So when you turn the key to on, no dash warning lights and gauges turn on? Did you check the fuses with a voltmeter or test light? With key off, some fuses would have power at all times-brake lights, headlights, horn- but with key on, all fuses should show power.

Just off the battery is the Battery Junction Block, where the power is distributed to various circuits through Fusible Links. These connect to battery power with eyelet connectors at the Junction Block-looks like 5 or 6 Links leading off the Block. Even the small wire from the battery to the Block is a Fusible Link, but if your headlights work, this main Link must be okay. One of the Links from the Junction Block would be to the ignition switch. If your ignition switch has power, you may have a bad switch, but you need to check if it has power first. If no power to switch, check the Fusible Links. The diagram I am looking at does not show which one it is, unfortunately.

sounds like a bad, burnt wire, or a blown fusible link. It runs on starter fluid or gas put in the air system, but the fuel pump, (electric) is not working. These types of problems can be hell to track down. Fusible links can appear good, but be bad. At any rate, its not any of the fuses inside the vehicle, it's either one under the hood in that box or a fusible link or bad wire somewhere under the hood. Basically your whole electrical system is out, so I would check main leads. Does the battery stay up even tho it's just setting? If it stays up, is not a dead short. Good luck, fixing it will be easy, but finding it a real pain.

I bet you saw some dramatic sparks when you hooked the jumpers up backwards!
The good news is that if your ignition switch was turned to the "off" position when this happened, the fix may be simpler and cheaper than you think. This car has one or more "fusible links" in its primary wiring. They may look like a thick piece of wire, but they act as super-fuses in the the case of large-scale power shorts and the like. Fusible links are typically in-line, so you won't see them in either your under-hood or under-dash fuse boxes. If you're lucky, you blew a fusible link right off the bat, saving the rest of your electrical system from serious harm.
If your ignition was turned to the "on" position when the battery was hooked up backwards, you have a more serious risk that you damaged your on-board computer. However, even if your computer were fried, your dome light, your hazard blinkers, and probably your headlights and turn signals (different circuit than the hazard lights, believe it or not, even though it's to the same bulbs) would continue to operate.
I'm going to recommend that you should check for one or more blown fusible links. Good luck!

Usually the power feed to the headlight switch isn't fused. It will come from a fusible link under the hood. On the right side of the firewall there is a black plastic cover, under it are the fusible links. Check here for a possible blown one. I would also suspect the headlight switch may have originally caused it to blow if thats the case. If you have already replaced the headlight switch, replacing the fusible link should repair the lights. Make sure you replace the fusible link with the same gage wire and same length.

check the main fuses (bigger fuses in the engine compartment fuse block)
if they are ok, check the ground wire from the battery for defects and the terminals and connection to the chassis for corrotion

bad ground cable,use a jumper cable from negative to alternator bracket, if it starts thats it.

I would check with vom voltage at battery terminals and at starter to ground. Is possible could be a fuse or fusable link but I think the positive goes straight to starter and power distribution fuse or fusable link