Kenwood kac-749s amp power indicator flashing red. what does this mean and what can fix it?

Either there is a short in the in the amp or hopefully just the speakers or wires going to the amp. disconnect any speaker input output and turn your amp back on(you will only have power, ground, and remote wires plugged in at this time) and if the red protect light goes away, then there is a problem with the input/output speaker wires, this includes your RCA's. If it's still flashing red then there may be a stray wire shorting to the amp in the speaker outs, other than that your amp may be fried. By the way, if it works without any speakers connected, including RCA's try connecting one component speaker at a time starting with your RCA's(if using them), speaker in, then speaker outs. If it turns into protect mode, note which speaker/RCA it was and replace or repair the short.