brake light / signal problems!!

Millertime1988 · February 21, 2016

Hey guys...sort of new to this forum. I use to post here fairly often back in 2010 2012 but kind of got away from me and I haven't been back. Unfortunately the email address linked to my old account is no longer in use. So I made a new account. Anyway let's get on with the help shall we?

I just picked up a 2004 sierra 2500hd with a 6.0l engine. 153,000kms. While driving it home at night I noticed when applying the signal lights no matter which side the opposite site would blink on the mirrors as well as on the dash. Come to find out when I got home that when applying a signal light the rear lights will alternate flash somewhat like a school bus (brake lights included) when applying the brake lights I had none.

I did some research and found that the flasher module was a very common issue in this particular truck so off to Napa I went. 40 bucks later I'm home have the dash appart and it's changed in 10 minutes. Turn signals on and i think yes! It's fixed. Which it somewhat was? Right signal - ok left signal - ok brakes - ok. But when I hit the signals and apply the brakes at the same time we are back to square one.

Now here is the kicker. I read about the bulb sockets possibly being faulty abd shorting out. So I removed the pass side brake light. Apply signal on pass side abd brake. Same problem. Apply driver side signal and brake. No issues. So I decided to remove the driver side brake light to see if there was a diffrence. There wasn't. Driver side works ok. Pass side doesn't. But with both bulbs In both sides are wonky.

Needless to say this is pissing me off and any guidance would be greatly appreciated.

I apologize in advance for the terrible spelling and punctuation I had a 3 year old crawling all over me while typing this.

Millertime1988 · February 21, 2016

Also I might add before the flasher module replacement the lights would go wonky with or without the brakes applied. Also when I applied the signal lights the little red light on my brake controller (reese) would flash which u found odd. But now after the flasher replacement that does not happen. So replacing the flasher module did indeed change something for the better but did not fully rectify the issue at hand.