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Flasher module location

Hunner

Well-Known Member
Messages
2,334
Location
Arkansas
I need some help.
My driver side rear tail/brake/turn bulb all stay on all the time. Other flashers work.
I can hear the flasher clicking but cannot find it. Got three bad discs in my back and can only stay upside down and backward for a short time. Yeah gettin old.
im thinking it may be a bad flasher?
All others work front and back.
 

alrock

El Diablo
Staff member
Messages
10,667
Location
Scottsdale
It's my understanding that the flasher is controlled by the BCM; there is no separate relay or control. The flashing sound is coming from a speaker, not a relay.

I think Happy Hummer's troubleshooting is on target. That trailer wiring (used or unused) is prone to fraying and shorting out. Wiring to the socket and the socket itself are logical choices.
 

Hunner

Well-Known Member
Messages
2,334
Location
Arkansas
There is no replaceable flasher , controlled by the BCM . body control module .
Turn Signal Lamps
The FRT/TRN/HAZ/CRTSY/MIRR and REAR/TRN/HAZ fuses in the underhood fuse block supplies battery positive voltage to the body control module (BCM). When the turn signal switch is placed in either the left or right position, a signal is sent to the BCM to illuminate the desired turn signal lamps. The BCM has an internal flasher that sends an ON-OFF voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is pressed, a separate ground signal is sent to the BCM to activate and flash all turn signal lamps including both IPC turn indicators. The front and rear turn signals are grounded at G105, G350 and G340. The sound for the turn signal indicators is produced by the IPC.
You have a bad Multifunction Switch Replacement
or BCM . You would need a GM Tech.2 scan tool To check the turn signal switch input to the BCM an to check out put of BCM to turn signal blubs . If a BCM needs to be replaced the scan tool is need to program it .
You
 

Hunner

Well-Known Member
Messages
2,334
Location
Arkansas
sooo after a week they determine in needs a new BCM! duh gm has none but NAPA and Oreilly do
I swear change from mechanics to technician and lost something in transition.
 
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