Starting issues with dimming headlights

2007 HYUNDAI SANTA FE

180,000 MILES • 2.7L • 6 CYL • AUTOMATIC

KERI JO CLENDENIN JOHNSON

MEMBER
2 POSTS

My car is having issues. It's very cold here. When I start my car I turn the key and all I hear is a click then when I turn the key again it starts just fine. Sometimes it takes a few tries and sometimes it starts the first try When I turn it the 1st time and it does nothing but click I still have power to the radio, heater, dash and headlights. Also, while I'm driving when I idle down the headlights dim for a second and the heater blower power decreases for a second also. We bought a new battery hoping that was the issue. It was not. Also the new battery is reading great but when I rev up the engine the battery voltage goes way down. Also the check engine light is on reading a bad o2 sensor.

Feb 12, 2021 at 5:50 AM

JACOBANDNICKOLAS

✓Experienced Mechanic
110,240 POSTS

Hi,

Based on your description, it sounds like the alternator is bad. You said the voltage drops when you rev the engine. It should do the opposite.

Also, the idea that you get a click and then it starts normally leads me to believe there is either a loose connection or the starter is going bad.

Lets start simple. I need you to check a couple things. First, make sure the battery terminals on the new battery are clean and tight. Here is a link to help:

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

Next, I need you to check the alternator output. Here is a link that explains how to do it.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Let me know what you find. Also, at a low idle, it isn't uncommon for the lights to dim and blower to slow a bit.

I will watch for your reply.

Take care and God Bless,

Joe

Feb 12, 2021 at 8:25 AM

KERI JO CLENDENIN JOHNSON

MEMBER
2 POSTS

I'm sorry. I didn't clearly explain when I rev the engine. When I rev it up and then let off the gas that's when the voltage drops way down. I'm taking it to my mechanic now tomorrow. He also cleaned the battery terminals two nights ago when I took it to him. He is going to look at the alternator also and the starter. He also thinks it maybe one of those causing the issues. Thanks for your suggestions.

Feb 12, 2021 at 10:47 AM

JACOBANDNICKOLAS

✓Experienced Mechanic
110,240 POSTS

Hi,

You are very welcome. If you can, let me know what is found. I'm interested in knowing.

Take care of yourself,

Joe

Feb 13, 2021 at 10:36 AM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.