xp190 I believe is probably correct. Check the fuse on top of the OVP (overvoltage protection relay). You'll see it back between the dual firewall area, it's a silver relay with a red piece of plastic on top, and also a flip open lid on top. Flip the lid open, there is a red spade type fuse under there, a red 10 amp fuse, I bet it's blown, this will blow if the polarity is reversed. It powers up the engine control module, it's running in fixed operating mode right now, which can give the high idle, poor cold starts, etc.
(that is, if it GET's cold in Manila!)