When I pull the knob to turn on the headlights there is nothing?

BMGRAY4599

MEMBER
2005 CHEVROLET IMPALA
V6
2WD
AUTOMATIC
160,000 MILES

When I pull the knob to turn on the headlights there is nothing. But once pulling that knob the four-way lights come on in the dash. Then when I proceed to turn the left turn signal on the four-way lights begin to blink faster. The same goes for the right turn signal as well. Now when I unplug the whole headlight unit to check if all wires running to it are getting power. Well, they all are except the light blue and dark blue one plus the yellow one as well. So, what do you think may be causing this for me or what I could do to resolve this matter?

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
47,643 POSTS

I would check the fuses first. here is a guide to help and I have included the fuse locations in the diagrams below. Check the fuses with the key on.

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

If the fuses are okay, I would remove the rear light bulbs to make sure there are no burnt or melted contacts. Please check out this guide to see what I am talking about:

https://www.2carpros.com/articles/no-tail-lights-exterior-running-lights-tail-lights-out

Is this a police model? I see a BCM is working the headlights but not the running lights. Here are the wiring diagrams for the headlamps and running lights so you can see how the system works. Check out the images (below). Please let us know what you find. We are interested to see what it is.

Images (Click to make bigger)