Put an alt. in the FC a couple days ago, now all of a sudden the battery keeps dying after like ~5 hour stints. Did absolutely nothing else other than change the alt. I'm at a loss. Any thoughts? It's a 91 N/A. The alt. was used from an 86. Took the car to the local parts store and they did a battery/alternator test. Everything checked out fine.

???

 

I've heard those battery/alternator testers are not always accurate.


Sounds to me that if it dies while you're driving it, then you got a bum alternator or corrosion on the wiring.


if it is dead after sitting a few hours, I'd say you're leaving a light on.




Hah, did you know the boxes behind the seats have lights in them?

 

No lights on. Removed the whole rear interior long time ago, including the bins/lights.

Again, car has never died in the past...

 

I had this problem. It was the alternator, i'm never gonna trust those bench test from parts store again. The Ex-alternator was tested 100% fine but after several weeks of car dieing while driving, finally found out it was the alternator. Changed it and it worked fine. If it doesn't dieing while car running/driving then it's not the alternator, it's either bad battery or a drain somewhere. If it's a drain, good luck finding it cuz it's a pain.

 

Yeah, the car does absolutely nothing adverse while driving. It's charging at 13-14, right where it should be. Only after sitting for about 5+ hours does it die. I drove it all day today on and off no problem, but after it sat from like 7-12 tongiht, it was dead, barely cranked at all.

 

Check the archives, the wiring for the alt is different between S4 & S5.

 

Well, pretty much confirmed it's not battery related. I just killed my MR2 battery trying it...I guess I got a bad alternator.

 

sounds like you have a drain somewhere but get yourself a multimeter they work great!

 

juat read this +1!!