Left rear blinker issue?

HARDWICK2024

MEMBER
2007 DODGE MAGNUM
5.0L
V8
2WD
AUTOMATIC
150,000 MILES

When the left blinker is engaged, the front flashes rapidly and the read doesn't light. I replaced the rear 3 bulb wiring harness and it fixed the problem for 24 hours and now it is back. I was going to check the BCM next but don't know where it is. Any other tips? Things to check?

Sunday, August 10th, 2025 AT 7:41 AM

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

The left blinker signal comes from the front control module which sounds like it is out, here is the location so you can swap it out. To be sure you can do a CAN scan which this video can show you how.

https://youtu.be/u-4syLc-ifQ

If confirmed here is the location of the FCM. Check out the images (below). Please let us know what happens.

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Monday, August 11th, 2025 AT 8:50 AM

HARDWICK2024

MEMBER
2 POSTS

Before I commit to buying a new FCM I did a CAN scan first. It throws two codes. B1643 Left turn lamp control circuit low. U0019 CAN B bus. Does your original suggestion hold?

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Thursday, August 14th, 2025 AT 6:42 PM

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

The fact that the problem went away for 24 hours and then came back usually is the controller, but you might have a wiring issue, so lets check them by following this guide and these wiring diagrams.

https://www.2carpros.com/articles/how-to-check-wiring

Check out the images (below). Let us know how it goes

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