For over the past two weeks I have had to jump start my '06 TL everyday in the morning before work and in the afternoon to leave from work. I finally changed out the both the positive and negative battery cables on 6/29/17. After changing the cable I did notice that the positive cable was corroded inside the cable. My car started right up but after sitting overnight, it did not start again this morning. I had the battery and alternator checked and both came out good. Any suggestions as to what my be causing the issue?

 

How old is the battery? Having it tested and coming up as good - doesn't necessarily mean that it is. Many stories of batteries that tested good - truly aren't.

 

The battery is a year and half old.

 

Not sure if you've ever heard of disconnecting the handsfree link - a common feature on our cars that go bad and draw battery current even when the car is off. There are youtube videos on how to disconnect it, it's pretty easy.

 

^^^ This is common, so might be worth a try.

 

This is probably a long shot but I've had a similar issue where my car wouldn't start unless the battery was fully charged. Turns out I had to replace my ECU.

 

Just dealt with this, here's my thread:

https://acurazine.com/forums/3g-tl-p...-works-956958/

Short answer in my case - problem was the AC Compressor Clutch relay.

Long answer....battery was 4 years old first time it died and tested weak, so I bought a new one. That one started dying in a couple of weeks. I disconnected the Bluetooth HFL, but that didn't cure it. Took it to a shop. They diagnosed it as the new battery being bad, and put a new battery in. That started dying on me in 3-4 weeks. Took it back to shop. They said alternator was fine. Diagnosed it as bad ECU, but said pulling the fuses must've reset the ECU and car was starting up fine. Until a day after I brought it home and it started dying again. Swapped the relay out last week and have been fine since.

Can test if it's the bluetooth module by physically touching the area to see if it's warm after the car has been off, and/or disconnect it to see if that solves your problem. The relay is only $5-7, if disconnecting BT doesn't solve it.

The proper way to find a battery drain is use a multimeter to measure current draw when car is off, then pull fuses one by one to see which circuit is causing the drain.