Starting problems and dash dimming

I have a 2005 Corolla. I have owned it 3 years and it was good for the first year or so. Then the 2nd year the colder it got the harder it was to start. I figured the battery didn’t have enough cca. I took it in and had the starting system checked at a local auto parts store. All was well but the battery only had 330 cca. So I replaced it. It was good for a month and then it started the same starting problem. The car cranks for a long while, just a few seconds but still longer than normal, then it starts and grinds like I have tried starting while running. This problem has gone on nearly a year and has yet to burn out the starter. Last week I noticed the dash got extremely dim when the headlights came on. I thought maybe the alternator was on it’s way out so I tried revving the car to see if the dash would brighten. It did not. This has gone on a week or so. Wisconsin is going have another cold snap tomorrow so I decided to get the battery tested again. This time 477 cca and the battery is rated 640. I returned the battery to Walmart. They said it needed to be charged but then discovered the battery wasn’t holding a charge and needed replacement. I thought issue solved. Got in the car and went to drive away, same issue. Headlights came in and the dash and accessories go dim. The starting issue was a bit better but still long. I’m not sure what steps to take now.

I suspect your alternator is defective.

Anytime you go to start an engine and the lights dim, either there’s a poor connection to the battery or there’s a problem with the starter.

Tester

You’ll need to have the alternator checked. Also, check the dimmer knob. The dash and accessory lights are supposed to dim when the headlights go on, and if the dimmer is turned way down, the lights could dim a lot more than you’re used to.

I’ll check the dimmer switch that is a very good idea. The lights don’t dim when I am trying to start it is when the headlights turn on. Whether by the solar meter or manually.

You may have a defective alternator causing excessive AC voltage to the battery and thus damaging it. Have a shop check out the charging system and not just the battery capacity. Make sure they check the AC voltage along with the DC. There should be nore more than .1 volt of AC voltage across the battery while the engine is running around 1,500 RPM. Max DC voltage should be 15 VDC. There could also be a problem in the wiring between the alternator and the battery. Make sure the battery clamps are clean.

Thanks for the numbers cougar. I have the stuff to test it in our shop but it’s too cold right now. But the numbers will help me in diagnosing. I do deserve bonehead of the year award though. I found he dimmer switch was turned down just a notch. Still took a bit long to start but was alright considering we are in the negative teens today.