2004 Honda Civic LX..The entire electrical system pulsates, along with it the engine while driving..New battery and had the alternator tested three times..Replaced ground wires too..Been driving it like this since February. Sometimes it runs normal on any type of weather. What could be the problem?
My car has a manual transmission.
Hello, Quite often, electrical system surges are caused by damage to relay components. If the fuel pump or ignition system relay is damaged, it may cause the engine RPM to rise and fall or cause the pulsating symptoms you’re experiencing. The only real way to determine what’s going on with your Honda Civic is to have a professional mechanic complete an electrical system inspection.