We get a lot of questions about the turn signal bulbs for 2008-2014 Impreza /WRX/ STi . Here are the most common:
Q: How do I install these? I can't reach the bulbs.
A: To reach the driver side bulb, remove the battery. To reach the passenger side bulb, remove the factory airbox. If you already have an aftermarket intake, you may be able to reach the bulb without removing the intake.
Q: Where is the blinker module located?
A: It's underneath the driver side dash, by the steering column. Turn on the turn signal, stick your head down there, and listen/feel for it. Just unplug the harness from the module; removing the actual module is difficult and not worth the trouble, if you ask us. You can zip tie the new module in place near the old one.
Q: My turn signal bulb doesn't work or stopped working correctly.
A :This is mostly likely due to a known wiring issue on the 2008-2014 cars. The wiring to the socket for the bulb starts to pull out of the socket because of too much tension. This is sometimes due to the wires being twisted, and simply un-twisting them can alleviate the issue. Otherwise a trip to the dealership may be in order. Come prepared, though -- they most likely will tell you they have never heard of or seen this issue. So keep this handy, below;
2011 Subaru Impreza Exterior Lighting Service Bulletin 307175
NHTSA: Action Number: 10038287 Service Bulletin Number: 307175
Jan 01, 2011
Summary: Subaru: turn signals may blink too fast due to tension in the bulb socket wiring. 2008-2011 Impreza