When i pull the cord all it does is makes a clicking noise but doesnt start

If the computer functions when plugged in with or without the power cell, you ok. Just replace the battery. Many times the power plug is at fault. This happens over time because the power cord may accidently be pulled out, (like if someone trips on the cord and pulls it from the laptop). The end of the power cord may become loose, and if so it will not make 100% direct contact between the power transformer and the line in to the computer. You cannot let the power cell (Battery) die. Some computer require a healthy Cell be operational in order to start up and function normally.

Electrical doesn't affect the engine mechanically. Besides making it run rough or shutting it down. Engine mechanical does affect the electronics though. Sounds like you have an electrical problem that needs attention. Also sounds like you have an engine that just threw rod/main bearings. At 4500 miles, I hope you have a warranty on this engine.

Sounds like it has a bad capacitor in it, or it could be a short on one of your speakers or wires running to the speakers. A short will cause the unit to get hot and it will shut down to keep it from further damage. Check your Ohms at each speaker and you should have between 2-8 Ohms per line. you also may need to check the connections coming out of the units connectors. Make sure that they are all pressed on tightly and not coming loose or not fully making connections, check all fuses, check all grounds and clean off the area where the ground is maybe moving it to another spot right away.

check the clutch the the starter engages into for binding

Fuel pressure regulator or fuel pump

try replacing the input cord between the speakers and the computer. the scratching noise normaly comes from a faulty connector. if that doesnt work you may have dirt or dust in contact with the speakers cones or there is an amplifier issue

Those units are designed to be fan cooled after the bulb shuts off. When the cord was pulled, the unit lost power and without the fan, sat there and cooked. Could be a thermal fuse, could be the bulb.

My 2004 Kia Rio just started losing compression and died on me. I tried starting it and it only clicks. I checked the battery cables and they are not corroded and very tight. Could it be the battery or the alternator not charging the battery? there is no water in the oil and it's not the water pump.

If you have recently fitted new hardware. Take it out.
If not, buy a power surge protector from your local pc store

Sounds like the starter.