Left blinker works, but left daytime running light does not.

I would check fuse and relay for daytime running lights
https://www.autogenius.info/pontiac-g6-2006-fuse-box-diagram/

Check the parking light fuse first. Then check to make sure the switch is actually providing power to the circuit

Year Make and Model,???
Your problem is in or under the fuse box.

it indicates that the earth points for the indicators are earthing back through the running lights earth system
if both low beams are not working I would suspect power supply ( relay) rather than both bulbs
if the vehicle is a ford I would suggest that the light control module may be faulty

Headlamps Inoperative - Low Beams

Step

Action

Value(s)

Yes

No

DEFINITION: This diagnostic procedure should only be used if the high beam headlamps are operating properly and the low beams are inoperative.

1

Did you perform the Headlights System Check?
--
Go to Step 2
Go to Headlight System Check

2

1. Turn the headlamp and panel dimmer switch to the ON position.
2. Move the headlamp dimmer switch to the LOW position.
3. Backprobe the headlamp dimmer switch connector with a J 35616-200 from cavity A to ground.

Does the test lamp light?
--
Go to Step 3
Go to Step 5

3

1. Remove the daytime running lamp relay.
2. Connect a J 35616-200 at cavity G5 to ground.

Does the test lamp light?
--
Go to Step 4
Go to Step 6

4

1. Re-install the daytime running lamp relay.
2. Backprobe cavity B at the high/low beam headlamp with the headlamp dimmer switch in the LOW position.

Does the test lamp light?
--
Go to Step 7
Go to Step 8

5

Replace the headlamp dimmer switch.

Is the repair complete?
--
Go to Headlight System Check
--

6

Repair the open in CKT 359 (PPL) between the headlamp dimmer switch and the daytime running lamp relay.

Is the repair complete?
--
Go to Headlight System Check
--

7

Replace the high/low beam headlamps.

Is the repair complete?
--
Go to Headlight System Check
--

8

1. Inspect for an open in CKT 12 (TAN) between the daytime running lamp relay and S120, repair as necessary.
2. Replace the daytime running lamp relay if no open was found in CKT 12 (TAN) between the daytime running lamp relay and S120.

Is the repair complete?
--
Go to Headlight System Check
--

The problem was a bad left front blinker socket that was grounding out

Have the multi-function switch and its circuits tested. The multi function switch is the blinker arm and the components its attached to in the steering wheel column. The multifunction switch has to do with blinkers, cruise control, wipers, wiper spray, high beams and also tied in with headlight dimmers/daytime running lights(if applicable) and hazards usually.

A good place to start.

Sounds like you need a bulb,the daytime running lights send power to the high beam wire so they look like low beam lights are on but really they are high beam lights running on low voltage.

the lights are controlled by a module, it is the DRL module, replace it. also try this
On the inside of the car next to the light switch there is your dome light button. GM made it to where you could turn off the daytime running lights by pushing it three times in and out. Turn the vehicle on then do this. Your daytime running lights should work after this.

I had this issue with my 1999 C1500.  I had to jump my truck a couple of times, because I left the inside light on and I found when I did this my daytime running lights worked briefly.  I wondered why, but didn't give it much thought.  I had to replace my battery a couple of months ago and my daytime running lights started working all the time.  Even though my battery would start my vehicle, run the interior components, etc., it didn't have enough voltage for the daytime lights.  Check your battery voltage under a load, see if it helps.