Recently, the car went through some minor accidents and repairs.

Catalytic converter was replaced
Water pump replaced
Driver front signal light was busted
Driver rear break/signal light broken

Few days ago, the car stalled while driving and now it won't start.
Reading through some great posts by txgreasemonkey, we checked the ecu fuse and it was blown. However, the new fuse blew again after running the car for about 5mins. It happened multiple times.

If circuit is shorting, where and how do we check? Or is this a symptom of a more serious problem?

Also it has a fluctuating RPM at idle.

Your advices are much appreciated thanks.

Check wiring for damaged or shorted lines..! It happened with me once that when I was testing the fuel pump voltage.. I used the ohmmeter scale instead of voltage and I blew two fuses... one of them was the 15 A under the hood and 7.5 A in the fuse box. Make sure when replaced.. you used the exact fuse rating.

I guess there is something wrong with the wiring.. that leaks (short) and when driving.. more power is consumed and blows out the fuse. Hard to tell where to check... may be those parts most affected.. like front lights for example.

When the car is off.. try to check all electrical circuits.. and that all functions well.. check lights.. for abnormal behaviour. Good luck.