08 G35 won't start after sitting a few days. Interior lights fade in and out along side a high pitched whine

After about 2 or 3 days of sitting, the car won’t start. Before garaging the car for the day, I’ll sometimes notice the dome lights and a high pitched whine will fade in and out along side jumpy revs while ideling. These symptoms are much worse with the AC / heater running and only happen occasionally. Turning the car off and back on seems to clear everything up.

Battery tested good. Alternator initially tested bad at AutoZone but later good by my mechanic before doing the replacement. Instead he did a parasitic draw test and found a CD changer was drawing too much. Unplugged it but did not resolve the problem.

The vehicle has been at the shop for two weeks with no updates and I’m starting to get worried. Any one have any experience with something like this?

Assuming (and that is dangerous) that the shop checked the electrical system and found it to be OK, I would dig deeper into why the car is not idling the way it should… maybe the IAC valve?

2 weeks seems like a long time, perhaps it’s time to make some phone calls and/or get a different shop to look at it.

Hey I called the shop today for an update:

They told they are unsure but think a faulty abs module could be the culprit and would later call back with prices and for permission to replace it.

The vehicle does have a host of dash lights glowing abs- vdc off - tpms - slip - AWD.

Have you ever heard of a case in which a bad abs module could be drawing excessive battery juice?