New battery, good alt. good starter, but car won't start, or get any power

[orangeblue]

Just like the title says, I have a brand new (1 day old battery) that has 587 CCA's and puts out 12 volts, but when its hooked up to my car, I get nothing. The reason I bought the new battery, is because it was doing the same thing with the old one. So then I got new terminals, and still nothing. But the weird thing is, my car can be jumped, and will run till I turn on the headlights, then the car either dies, or comes dang close, and I get the CEL light for a few second, and it sounds like the ECU clicks once when the CEL light shines. I'm stumped. Oh and also, it took a few days for it to get this bad. It started out with, when I would turn my car off, the battery would drain (or so I think) so I would just disconnect my negative battery terminal. Then reconnect when I wanted to start my car. But that even stoped working. ANY insight would be appreciated.

 

[robs90tsi]

Check for corrosion on your battery cables, check for a bad ground, sounds like something is still bad, and if its not the alternator or battery, it could be your cables are crappy.

 

[Rex2342]

Check the caps in the ECU iteself. DSM's are known for bad ECU's and since the ECU controlls all the battery and voltage stuff I would start there. I had a freind with a problem similar to this. His battery would die everytime he turned the car off. He went through 3 alternaters and 2 batteries before we found out his ECU was bad. Mine were leaking so bad it actually ate a hole through the ciruit board and the whole ECU had to be replaced.

 

[Liquidus]

What code is the CEL ?

 

[red_rs]

sounds to me like a coroded ground somewhere....check all of your ground and make sure there all tight and even take the time to take them off and sand them a little bit and put them back on

 

[UnlshdEclipse]

is the positive battery cable tightened down all the way on battery post? i had a problem with my car not wanting start, etc. only when jumped. come to find out it was a bad connection withe positive terminal/cable. so i replace both the positive/negative connecting points-fires up great.