My 2000 Honda Civic HX will not start

A simple trick to finding a short is to replace the blown fuse with a pair of spade terminals, then use small jumper wires to connect them to a 12 volt light bulb. A brake light bulb works well. When the circuit is live and the short is present, the bulb will be full brightness and hot so be sure it's not laying on the carpet or against a plastic door panel. Now you can unplug electrical connectors and move things around to see what makes the short go away. When it does, the bulb will get dim or go out.

You listed two different fuses so if we start with the assumption the problems are related I'd look for a wiring harness that fell down onto hot exhaust parts. Next, since we know someone added custom wiring and it's of questionable quality, the common things to look for are wires draped over sharp metal brackets and they've rubbed through the insulation, and wires that flex a lot or can get crushed. Cruise control wires usually include something attached to the brake light switch. That's a good place for them to get hooked on something.

The SRS system is the supplemental restraint system, (air bag). There isn't anything that can draw excessive current other than a short inside the computer or in the power wires going to it. There's nothing you can do to cause a short to occur in the computer so that leaves the two power wires to look at. Replace that blown fuse with the test bulb, then turn on the ignition switch. If the short is present the bulb will be bright. Start by unplugging the computer. Most likely the bulb will still be bright telling you the computer isn't the problem. It's in the wiring, and since that rarely causes a problem, I'd be looking for a cruise control wire that was tapped into one of those for its power source.

You may also get a clue when you wiggle and pull on wire harnesses. If the test bulb stays constantly bright the short is solid as in a wire crushed tightly between two objects or it's a shorted component. If the light flickers you're more likely to find a wire rubbed through and scratching on something metal. In any case the bulb will show you when you're in the right area.