Both the low beam and high beam headlights are not working?

MVANN74

MEMBER
2008 CHEVROLET IMPALA
3.9L
6 CYL
2WD
AUTOMATIC
173,694 MILES

Bulbs are good. Fuses are good. Daytime running lights and fog lights work. Removed headlight assembly to test power and ground. I have power on both pins on both sides. Could this possibly be a grounding issue? If so, where do I find the ground for headlights?

Saturday, December 9th, 2023 AT 11:00 PM

3 Replies

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Hi,

I attached the wiring schematic below. If the high beam works, the ground is good. That leaves a power supply which you indicated is present.

So, check the light socket and make sure it isn't corroded or damaged. Also, are you certain the bulbs are good?

Let me know.

Take care,

joe

See pics below.

Images (Click to make bigger)

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Saturday, December 9th, 2023 AT 11:40 PM

MVANN74

MEMBER
65 POSTS

Thanks for wiring schematic. High beams do not work. No corrosion or damage in either socket. The only lights that work are the DRL and the fog lights. No low or high beam. Bulbs are good. Fuses are good. Although I was reading something about a non serviceable relay on underside of fuse block. Some kind of circuit board. If that's the case will the entire fuse block need to be replaced?

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Sunday, December 10th, 2023 AT 12:19 AM

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Hi,

That is correct. There is a high and a low beam relay that is part of a printed circuit board and non-serviceable.

If you look at the schematic I sent, it indicates PCB, which is a printed circuit board. I have no idea why they do these things.

Let me know.

Joe

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Sunday, December 10th, 2023 AT 7:33 PM