2004 Grand Prix turning Signal lights wont work.

You have a body control module problem, more then likely . The BCM turns the turn signal on an off. Have a scan tool hooked up (a profesional grade scan tool ) One that can read codes in the BCM.

Turn Signal Lamps
The STOP/TURN/HAZARD fuse in the instrument panel (I/P) fuse block supplies battery positive voltage to the body control module (BCM) for the turn signal lamps. When the turn switch is placed in the LEFT TURN or RIGHT TURN position, ground is applied from G202 through the turn switch, to the turn signal switch signal circuit and to the BCM. The BCM then applies battery positive voltage to front and rear turn signal lamps supply voltage circuits. The left front turn signal lamp is grounded at G100, right front at G101, left rear at G301 and the right rear is at G302.


DTC B3948 Left Front Turn Signal Circuit

The turn signals operate off of the emergency 4-way flasher. Check to see if your 4-ways flash. If they do, your problem is the 4-way flasher module. Replace that. It's not too difficult and fairly cheap

Probly the wiring to it has resistence from wear. Or the switch

Hey I literally just today had the same problem, put a new bulb in the light was on but did not blink!!!! SUPER EASY SOLUTION, you simply have the bulb in too far. I gently pulled mine out a tiny bit and it started working fine... guarantee that's all that's happening to you!!!

Replace the flasher.

sounds like bulb in front is bad

you would need to buy a blinker relay

remove the 2 screws remove the light and replace the bulb

you have to acces the lamp and replace the bulb.

tnx

drcool