Picture of 2005 cobalt wiring harness for headlight

Should be fine as it is the same generation.

https://en.wikipedia.org/wiki/Chevrolet_Cobalt

...

http://www.google.com/imgres?imgurl=http://i1107.photobucket.com/albums/h381/Coby007/2006exteriorlighting.jpg&imgrefurl=http://pushedplay.com/2006/2006-chevy-cobalt-fuse-box-diagram.html&h=834&w=1023&tbnid=Vx1O8wWxbq9z8M:&zoom=1&docid=9LsYUkdOpm0MyM&ei=IQCbVa7MIY7JogSw2pDAAg&tbm=isch&ved=0CCUQMygIMAhqFQoTCO7g__XFx8YCFY6kiAodMC0EKA

http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f80cb1732You have fusible links tied into positive battery cable,they could be burnt or meled and not giving enough current so it is flickering,check all wiring leaving positive battery cable and all fuses in fuse box in side Cobalt.Here's a electrical diagram of a 2006 colbalt,for some reason,the 2005 is not listed,but you will see the fusible link.Click on link.

No - the worst electrical problem that the headlamp harness could cause is to short itself to ground somehow (bare wire, unplugged & turned on, etc), which would blow the headlight fuse.
However, dashboard problems can cause headlight problems, since the headlight switch is located in the dash.
The common point between the headlight problems, dashboard problems, and "electrical problems" would be the under-dash wiring and/or wiring harness from ECC (Engine Control Computer, aka "the car's computer) to the dashboard - check here first for grounding/shorting problems, or water leaking out of the in-dash vents onto a wiring harness.

are u certain it needs to be--thats a job for pros--whats the problem...

Instructions Things You'll Need:

• 9007 LL halogen headlight bulb
• Wrench
• Gloves or clean rag

1. Step 1 Set the parking brake and remove the keys from the ignition to ensure your Chevy Cobalt won't roll while you're replacing the headlight bulb.
   
2. Step 2 Open the hood by pulling the hood release latch located under the instrument panel on the driver's side of the car. Locate the secondary release latch on the front of the hood at the center, slightly towards the driver's side. Slide the latch to the left to release the hood and raise it.
   
3. Step 3 Locate the headlight assembly and remove the bolts by turning them counterclockwise. Set the bolts aside in a safe place, so you won't misplace them.
   
4. Step 4 Remove the plastic fasteners from the headlight assembly molding. Carefully pull back the front fascia, or molding. You may need an extra pair of hands to perform this slightly awkward task.
   
5. Step 5 Grab the headlight assembly and pull it towards the radiator at a slight angle to remove it. This should provide easier access to the headlight bulb and wiring harness.
   
6. Step 6 Lift the plastic locking tab on the wiring harness to disconnect the bulb base. Then, disconnect the wiring harness from the bulb socket and remove the black retainer by turning it counterclockwise.
   
7. Step 7 Disconnect the bulb socket by turning it counterclockwise. Remove the old bulb from the socket by firmly, but gently pulling it straight out.
   
8. Step 8 Replace the old bulb with a new 9007 LL halogen headlight bulb. Put your headlight assembly back together by reversing the steps when you disassembled it. Use 89 inch-lb torque when retightening the headlight assembly
   

automatic headlights are controlled by a photo sensor on the dash located in front of the Instrument cluster. to test the sensor try covering it and see if the headlights come on. faulty wiring in the circuit could also cause this problem. the headlights and the radio are wired together and the "auto" function will cause the radio to get brighter when its dark out, thus the combination of problems.

check:
1. the light bulbs
2. fuse(s)
3. check/replace the flasher relay in the fuse panel(front left of engine compartment).
If all of these check out it could be the signal stalk

Open the hood by pulling the hood release latch located under the instrument panel on the driver's side of the car. Locate the secondary release latch on the front of the hood at the center, slightly towards the driver's side. Slide the latch to the left to release the hood and raise it Locate the headlight assembly and remove the bolts by turning them counterclockwise. Set the bolts aside in a safe place, so you won't misplace them.Remove the plastic fasteners from the headlight assembly molding. Carefully pull back the front fascia, or molding. You may need an extra pair of hands to perform this slightly awkward task.Grab the headlight assembly and pull it towards the radiator at a slight angle to remove it. This should provide easier access to the headlight bulb and wiring harness.Lift the plastic locking tab on the wiring harness to disconnect the bulb base. Then, disconnect the wiring harness from the bulb socket and remove the black retainer by turning it counterclockwise.Disconnect the bulb socket by turning it counterclockwise. Remove the old bulb from the socket by firmly, but gently pulling it straight out.Replace the old bulb with a new 9007 LL halogen headlight bulb. Put your headlight assembly back together by reversing the steps when you disassembled it. Use 89 inch-lb torque when retightening the headlight assembly bolts.

there is a problem with the fuses getting wet under the hood, it has been causing alot of problems with headlights you may want to check there for anything