Quote:
Originally Posted by mcaval465
The most notable thing is the moment I hit ignition, the voltage drops across the entire car. From ~12.4 V to 9 V or less, you can even see the cabin lights flicker. Also notable is that the + cable that connects to the starter near the ECU and B+ post fluctuates in voltage randomly when the car is awake. It seems like when the car is awake every ~5-7 seconds it dips to 8 V and then back to 12.4 V. The other two positive posts/connections have a solid 12.4 V. I also measured from chassis ground to the engine and the alternator case and get a solid 12.4 V.
|
The telling symptom is the voltage drop when you place an electrical load on the system. Since you've already dealt with the most likely cause, the engine ground strap, the next most likely problem is a B+ supply line.
The most common failure mode that fits your symptoms would be corrosion on the positive battery cable from the distribution block on top of the battery to the pass-through located at the bottom front of the battery box. Water entering the battery box from leaks involving the trunk, tail light or gas filler neck seal can cause this problem. Pull your battery and inspect - wiggle the lead. That distribution box/fuse box on top of the battery may also be a culprit.
Would help to know the exact build date of your car as the specifics of the power distribution varies. Look it up yourself at
www.newtis.info
I would not buy an alternator or voltage regulator as suggested above.