2005 Corolla Stalling on Idle or with Accessory Power-Up

[jctorra]

My 2005 Corolla started stalling constantly a few days ago. With no signs or warning this problem suddenly started. I could not start my car and the battery was dead. Being parked at the top of a hill I let it roll and popped the clutch, the car started right up, but as soon as I turned on the headlights it immediately stalled.

I jumped it and returned it to the top of the driveway where every 10-15 seconds the headlights would dim and the car would almost die, but seem to kick itself back up. I left it in the parking space and went to Autozone, where they seemed to agree with my bad alternator theory. After special ordering the alternator and replacing it three days later I am back at the same problem. New alternator installed I pop started it down the hill again. The only thing I notices was a slight humming/buzzing sound (can't describe it well, didn't hear it for too long. Maybe breaking in the new drive belt I installed while I was under the hood. But as soon as I turned on the blower for some A/C it stalled out again.

Another jump and trip back up the driveway where the stall problem got worse. Only while reving the engine can I keep the car running, and adding any accessories, like A/C, lights, etc will drag me into a stall again. With the stall comes dimming indicator lights, and all.

So now I'm $129 deep on the trial and error technique with the purchase of a new alternator.

Hopefully someone else has experienced this problem and can enlighten me as to what it may be. Thanks!

[karazy]

You may have installed a faulty alternator. Check the O/P at the battery. Did you have the battery tested, while you were there?

[jctorra]

I was afraid of that.... Battery tested bad, but my local store is sold out, not going to be able to test that theory until tomorrow. But would the car be doing this with a bad battery? In theory I should be good to go once I'm started up anyway? right?

Originally Posted by karazy

You may have installed a faulty alternator. Check the O/P at the battery. Did you have the battery tested, while you were there?

[karazy]

Most alts won't put out the full req'd power at idle. It usually takes until about 1200-1500rpm to start and with the draw of a bad battery on the system, the problem is compounding. You should be getting around 14.5 VDC at the battery posts, with the engine running.

[tarbasd]

I disagree. Your alternator should provide plenty of power at idle. At least your engine should run without revving.

I think you have a short circuit somewhere. Here is a suggestion: since your battery is no use anyway, just take it out. Get a jump, and see if the problems persist. The car should idle smoothly with no battery (don't turn on accessories). If that's the case, then your battery is the culprit - it draws power while your engine is running - and all you need is new battery. If not, then you probably have short somewhere else.