1990 Nissan Sentra

If you have another vehicle to get a jump start, that would be good. Make sure that you don't reverse the polarity when you jump start the vehicle.

OR

Get a multimeter and check the voltage on the battery. If the battery has around 12.6 volts, then check the cable connections from the battery to the fuse box and starter. Make sure both cables are tight and no corrosion. Next check the fuse box under the hood. Connect your multimeter on the cable connection to the fuse box, just to check that you still have power (should have similar voltage). You main fusable link should be either 80A or higher. Check voltage there too. Just keep checking all fusable links and fuses until you find the right one.