Bad ECU = Dead battery?

[xxREVERBxx]

Would a dying or bad ecu cause my battery to die? I'm not sure if its my alternator. I checked belt tension, that's fine. Jumped the car let it idle for 5 minutes, pulled the neg. terminal and the car died. Does that mean my alternator is bad? Would this be ECU related? Leaky caps? Just trying to root out all the possibilities. If it it the Alternator, could i rebuild it? Thanks for the help guys.

 

[bones_420_99]

Ecu causing battery to die I couldn't tell you but as far as alternator goes yes it can be rebuilt. Best bet to do is take your car to like an Autozone or Pep Boys or some other automotive shop and have them test it. This was happening to my finaces Explorer and it was just bad connectors on top. Cleaned the connectors and everything was gravy. But definitely have the alternator checked first before going away from it and looking at other parts.

 

[xxREVERBxx]

When you say connectors are you talking about the battery terminals? Or the alternator connections?

 

[bones_420_99]

Sorry about that I meant the terminals. I would take a wire brush to them and make sure they are good and cleaned then if that doesn't work have the battery and alternator checked out. Autozone will do it for free and if alternator is bad you can get it swapped out there. They should have them in stock if not might be a couple days. Let me know if this helps you out.

 

[mastadogg2]

If it was a bad ecu it wouldnt start period for the most part. definitly sounds like an alternator issue if it dies after you pull off the negative terminal, the alternator seems like the only thing thats keeping it running, try looking at your interior lights when you rev the car up do they become brighter? if so your belt is either bad or your alternator is about to go out if its not fully out now

 

[steve]

Bad alternator or blown alternator fuse. Check the fuse first, it's a lot cheaper than the alternator.

Steve

 

[mastadogg2]

Bad alternator or blown alternator fuse. Check the fuse first, it's a lot cheaper than the alternator.

Steve

very very good point. I had that happen to me and i changed the alternator and i was like uhhhhhhhhh? then checked the fuse and felt like a dumbass

 

[steve]

I really don't care for pulling the battery terminal as an alternator check. It's risky and can cause voltage spikes that could destroy the electronics in the car. It's far safer to check the voltage at idle and see if it's above 13v. If it is, then alternator is charging, maybe not well but charging.

Steve