Headlight and brake light issue

2005 CHEVROLET TRAILBLAZER

160,000 MILES • 6 CYL • 4WD • AUTOMATIC

GAMRCHEF

MEMBER
2 POSTS
FOLLOW

Last night I replaced a burnt out brake light bulb on the driver side and checked that it was working. This was while car was turned off. When I turned on the car a few minutes later, I noticed that the driver side headlight is out, which it wasn't before the brake light bulb swap. I don't know if it is an important piece of information, but the lights are set to auto. Coincidence or something else? Someone suggested to me I might have a "dead short." What is that and how do I find it?

Feb 26, 2021 at 1:25 PM

JACOBANDNICKOLAS

CERTIFIED EXPERT
110,175 POSTS

Hi,

The brake lights are on a different circuit, so chances are it is a coincidence. Have you replaced the headlamp and are both still working?

Let me know.

Take care and God Bless,

Joe

Feb 27, 2021 at 6:51 PM

KASEKENNY

CERTIFIED EXPERT
18,907 POSTS

More than likely it is a coincidence. The reason is, the tail light and head light are completely separate systems. So I would just figure out why the headlight is not working at this point.

I attached the wiring diagram below for your review.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-replace-a-headlight-bulb

Let's run through this info and let me know if you have questions.

Images (Click to enlarge)

Feb 27, 2021 at 6:51 PM

GAMRCHEF

MEMBER
2 POSTS

Thank you for your replies. No, I haven't changed the bulb yet. I've got to swap out brake pads tomorrow and just added that to the list. I was kind of thinking the same thing about different circuits, but don't want to say coincidence. Last time I said that, my son's heater blower motor went out and battery went bad 2 days later. Well a couple jumps later, while waiting for funds to get blower motor, I disconnected the motor from the electrical system and voila no more battery drains! I'll keep you posted.

Feb 27, 2021 at 7:29 PM