Directional disorder

[Roger.T]

Hi I bought a used 2005 Sierra just over a year ago. I understand my question is a bit wordy lol(just tryin to give a full picture of the issue) please read through.

It's had annoying but minor electrical issues from day one. But now it's causing Inspection failure. 

 When no running or headlights are on, the directional work perfectly. For the last 6 month's, when the lights are on, even without turning the signal on, the left(and only the left) signal stays solid. And 2 or 3 of the Less on the side mirror stay out. The right side still works fine. I've changed the signal lever and the module with no change.

I might add, one of the original issues were when the lights were off the After market radio will be just static.. Turn the lights on and the radio works fine(hoping that helps diagnosis).

I'm a carpenter so no truck = no work

Thanks all for any suggestions

Roger

[Havasubum]

In my experience when weird thing occur electrically, it's usually a bad ground. GM vehicles do have ground issues as they age.  Good luck.

[Jsdirt]

Yeah, this is screaming a ground issue to me as well.

[It's Tim]

Change the bulb, then the socket.

[Roger.T]

Thanks guys. I haven't dug that deep yet(like I said, carpenter not a mechanic lol). I'll start poking around tomorrow.

So would be safe to assume I should start at the headlight circuit? Also, when it first started it was random and one of my guys suggested it was cause I replaced the headlight bulbs.. Any thoughts?

[Roger.T]

3 hours ago, It's Tim said:

Change the bulb, then the socket.

Thanks. Seems like a good of place to start as any. Is there a way to test it with my volt meter?

[It's Tim]

Here's one:

 

[Roger.T]

Thanks Tim, I appreciate it. Hopefully I get a couple of hours of decent weather today

[Doug_Scott]

  I would first locate where you can disconnect each light from the factory harness at the point closest to the socket. This should help you locate any bad sockets. 

If you are missing  couple of LEDs in the mirror that may cause issues.  LEDs do not draw enough power as it is, if you lose some it may do odd things.  Pretty sure you can simply disconnect the mirrors completely to rule them out. 

 

Clean every ground connection you can find, if your aftermarket head unit is metal, run a ground wire to the chassis of the head unit. 

[Roger.T]

11 minutes ago, Doug_Scott said:

  I would first locate where you can disconnect each light from the factory harness at the point closest to the socket. This should help you locate any bad sockets. 

If you are missing  couple of LEDs in the mirror that may cause issues.  LEDs do not draw enough power as it is, if you lose some it may do odd things.  Pretty sure you can simply disconnect the mirrors completely to rule them out. 

 

Clean every ground connection you can find, if your aftermarket head unit is metal, run a ground wire to the chassis of the head unit. 

Thanks Doug that sounds good. The weird thing about the mirror is it only loses a couple of leds when the headlights are on. Otherwise they all work.

[Doug_Scott]

12 hours ago, Roger.T said:

Thanks Doug that sounds good. The weird thing about the mirror is it only loses a couple of leds when the headlights are on. Otherwise they all work.

Sounds more like a bad ground or bad bulb. Sometimes one of the filaments in a light bulb will break and drop down and connect to the other filament. It will then backfeed the other circuit.  LED bulbs normally won't allow the backfeed to occur, but incandescent bulbs do. If you get a new bulb you can do the "find the bad xmas string bulb" routine where you change one bulb, check if it changes, then if it doesn't change move to the next bulb and use the bulb you just removed. Rinse and repeat. 

[carkhz316]

Check your bulbs. One or more of your parking lights or turn signals are out.

[Roger.T]

Thanks guys. I'm gonna check all the bulbs today.