Swapped a motor in a few months ago, car ran fine since. And then, all of a sudden I've got electrical issues. Alt light comes on, at any RPM higher than idle, and I start losing juice instantly. If I leave it to idle, it will charge up enough to start again. I took it to autozone to test the battery and alternator. Battery was good, but the guy said it was running at 5 volts. (Maybe he was an idiot, maybe its actually possible. Don't know.) In that very parking lot, my main relay started clicking like crazy. I reset the ECU, the car started, and somehow got the car back to my driveway before complete battery failure, and I let it sit at idle so it would charge back up. As it was doing that, the ABS box would gurgle and spit until it got more power. If I turned the headlights on, the Alt light came on again, and the car would lose power fast to the point of stalling. When I thought it was charged enough, I pulled the key. I tried starting it since then, and the main relay just clicks really fast when the key is turned to run, and nothing happens when I turn the key to start.

Let me preface this by stating my ignorance on the subject. Please don't take anything for too obvious to mention. Having said that, I'm guessing this is either an electrical short (possibly bad ground) or a bad voltage regulator on the alternator (or even the ECU?)

I don't have a continuity tester or DMM yet, but I'll be getting one soon. Until then, does anyone have any ideas as to what this might be, or know of a troubleshooting technique for checking bad continuity, shorts, and grounds?

 

It does sound like a bad ground. Check all 3. core support- valve cover. trans-framerail. on the harness-thermostat housing

 

i giong to have to say i think it is a bad voltage regulater to because my car was doing something similar to that