adc27

I bought another sc400 a month or so ago from craigslist. It was non-running and sounded like a potential ecu problem. I took the ecu out of my other sc400 and went up there with it and it started right up. I went back to buy it a couple days later with the ecu and a new battery, since the one in the car was dead. The car sat for about a month or so, and I would occasionally start it up. I drove to school one evening, about 20 miles roundtrip. On the way back my radio went out, headlights went out, and dash went out. I managed to get home just barely. Figured it was the alternator. Installed a new alternator earlier this week. Took the car out for a good half hour or so to have some fun in the snow. Everything ran fine and the car was great. I started it this morning for my roommate to take it in to get an oil change and what not and he called me 5 minutes after I left and told me the car died and would not start, just click. Great. So I stop at home around noon to see if I can't get it started. Before doing anything I just try starting it and it starts right up with zero issues. I thought maybe it was just too cold this morning. I get home from work around 5pm and think that maybe the battery is almost dead so I'll just start it and let it run to get it charged. Start it up and within 2 minutes the radio turns off, the dash needles drop, and the dash turns off. I turn it off, and it only clicks when I try to turn it back on.

I'm kind of at a loss. Bad grounds maybe? Could my aftermarket amp be killing my battery? Why would it only click for him at 8am, but then start right up for me at noon? How come it ran flawlessly for me the day before with no issues? I just don't really know what I should try next.

MMCtuner

If accesories went out while driving then battery isn´t the problem. Re-check the alternator and look for loose/dirty grounds.
Good luck!

adc27

Guess I'll try to look up a grounding diagram. I just don't understand how it would start then die then not be able to be started. Then be able to start a couple hours later. Doesn't make sense to me.

Slaker13

Check your fuses under the hood, wiggle them around and make sure they are secure. My car would shut off unless I rev'd a bit and it turned out my MAIN fuse under the hood wasn't making a proper connection even though it was screwed in tight. You can also do some electrical tests with a multimeter to see if and what is draining your battery.
I doubt your amp is causing this, you can still try unplugging it though to see if you want. Clean your terminals and connectors too, it doesn't hurt to have a solid connection to the battery.

3L4jzz31

iTrader: (2)

Welcome to the world of SC parasitic drain, i think there's at least 10 different threads on this all pointing to different possible things causing the drain. Now that's out of the way, look at major fuses as slaker13 mentioned to see if any of those are bad. Next is to start hunting for loose grounds, or maybe a wire thats gone bad. If it comes to this, in all seriousness, I wish you the best of luck.

scENFORCER

This is a total random shot in the dark, but it doesn't hurt to see if there's any water pooling in your trunk under where the stock amp was (I'm assuming you got rid of it). The drain hose can come lose and pour water directly into your trunk instead of outside your trunk. If you have the old unconnected amp harness there it can cause electrical gremlins.

adc27

I think there was water in there at one point. It's surely all ice now. Should I just cut out all those wires? Thanks. Will look at fuses and other connections hopefully tonight and see if I can't find something.