My fiance has an 01 civic hx. They put a new engine in it about a year ago. A couple months back her check engine light would come on and the radio would stop working whenever she was at a high rpm or when the heater was turned up. I just unhooked it and it worked after that. but the second time it did it the stereo stopped working for good. I then put an aftermarket stereo in and the same thing happened. I ran a diagnostic and it said that output voltage was too high or ecu? Does anyone have a clue what this could be. I have heard that it could be electrosis, but I have no idea where to begin, and I don't want to buy a new ecu if it wont fix the problem!
Thanks

 

have your alternator tested it could be overcharging and causing a power surge, also make sure all your grounds are clean and have a good connection. do you have a ohm meter to get readings of the power supplied through the wiring?

 

I'll try it out thanks

 

I tested the alternator and it read out at 14.0 at an idle and while under load. The negative battery cable was a little beat up, but nothing too severe I checked the ground from the front of the block and it looked good. What other grounds do I need to find? and I do have access to a multimeter, where should I start?
Thanks for the help

 

The radio and heater probably share a ground connection somewhere behind the dash. Somewhere. The ECU is grounded to the engine by small wires connected to the thermostat housing (where the lower radiator hose meets the engine).

With engine running and lights on, confirm that there is near zero volts between the (-) lead post of the battery and the engine, also test the body ground the same way.