OK I was tightening a cable on my alternator on my 1990 honda civic HB and all of a sudden there was this spark and my car went dead now I have no power at all what's going on with it:confused:

. Test all under-dash and under-hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post252145

. Perform the K-Test on the ECM:

Remove the MAP Sensor connector and turn the ignition switch to ON (not start). Using a multimeter, check for 5 volts going between the MAP Sensor connector's reference wire (+) and ground. As you look at the connector, this is the socket on the right. Really press the black test lead into a cleaned main ECM ground on the thermostat housing. If the voltage is low, it's probably indicating ECM failure. Most failed ECMs will record a fraction of a volt.

Hopefully, you just blew a fuse. Because the FR Signal goes from the voltage regulator to the ECM, it's possible you shorted out the ECM (hence, the K-Test). Ensure the CEL comes on and goes off after 2 seconds, when you turn the ignition switch to ON (Position II). In the future, always disconnect the negative battery cable, before working around any electrical/fuel system on your car.