Weird prob- video attached

[jgmachine]

Ok guys- strange problem. My turn signal just stays on... If I eliminate the load by turning off the lights, it works fine. I thought it may be the battery, so I replaced it with no luck. The problem comes and goes. Sometimes it is fine. I just made the 30 second video to show...

Could it be a bad ground? If so where would it be? It is only the left turn signal that does this.

http://www.youtube.com/watch?v=uR9t3midONc&sns=em

Thanks so much....

[ryaleon]

Used to happen in my old Trans Am all the time. Blinker Bulb socket had gotten lots of moisture and was bad.

[fyr145]

These darn electrical problems ...............

Well lets start with the obvious and work back. Your getting power because the turn signal light comes on and the headlights come on. No fuses blown either......Power ruled out.

Next, the circuit has ground because the turn signal works when you turn the headlights on. No ground ruled out.

Then, the next thing I would check are the relays. They seem to work fine when the headlights are activated, but then the turn signal malfunctions when the lights are turned off. Suspect a faulty relay. Check relay. YouTube has short videos on how to check them. Just because your getting power, does not mean the relay is working properly. Your owners manual should tell you which relay to pull and from which fuse block.

In addition, I would unplug the turn signal relay and then retest the headlights and see if they come on like before.

Good luck

[HUMTECH]

Im thinking hazard/flasher module. it plugs into the back of the left ip fuse block. Its black or grey rectangle box. Try tapping on it with a screw driver handle while signal light is on and solid. If it starts to flash then that's the problem, even if it doesn't start to flash its the most likely culprit

[PaHumBug]

I agree with Humtech. Thermal flasher relay modules are finicky, if they don't have sufficient load they will not flash. But let's hope that the problem is with the flasher unit itself.

[jgmachine]

Thanks... Local parts store did not have the relay, so I had to order online. Funny thing is that the problem has not come back in 2 days. I did try working the hazard flashers when the problem last appeared. Maybe that causes some freak patch on the relay. I will replace nonetheless and hope for the best.

[jgmachine]

Installed new relay today. Problem is still there....

[jsbihn]

I would say it sound like a "short" of some kind
Now given, this doesnt mean "short" to make something pop or go out, I mean "short" as in a possible arc.

It sounds like you already checked the relays (It is funny, most of HT's answer start with banging on something... dont get me wrong... he is right, just funny how alot of problem Dx with these trucks start with banging - and sometime it ends with banging... like your head against something )

Have you checked load on your light when the headlights are turned on?
Does it change?
You have to check it all the way back.
Electrical issues are a PITA.
Also ask yourself was there any event that you might have done prior to this happening? (ie. you went for a swim?)

and Lastly and most importantly.... have you actually check the outside blinkers to see if it is a real system issue or just at your dash?
(it seems these dashs can be kinda finicky... I know HT told me something similar when my passlock light started to act up)

--- (again I have to say we are VERY lucky to have HumTech on our forum. Great guy, and knowledgeable too!!)
----- (actually I can say that about most of the guys on here!!!)

[fyr145]

Originally Posted by jgmachine

Installed new relay today. Problem is still there....

Time for step 2...........

If the relay has been ruled out, move to the turn signal bulbs. You say that it only happens on the left side. Start with either the front or rear bulbs and replace one bulb at a time with a new one.

Also look at the socket that these bulbs fit into. Do they look corroded? rusted? warped? Any sign that might indicate that the bulb might not be sitting in properly.

Look at the back of the wiring harness that the sockets come from and look for any exposed insulation or pinching/crushing in the area.

Lastly, just as a follow up, have a meter handy and check each bulb for continuity. Adjust meter to correct setting. Just because a bulb "looks" okay does not mean there my be a crack or some kind of tiny break in the bulbs wiring.

[HUMTECH]

Check body ground from battery neg terminal to left front frame rail above tow hook

[fyr145]

I was thinking that if he had a bad ground, none of these issues hes describing would even work, let alone work correctly.

[jgmachine]

Well since I posed last, the problem has went away. The temp has also increase from 0 to 30s and 40s. I still plan on replacing all bulbs, but what could be affected by temp???

[KTM640Dakar]

Ground is bad in bulb harness. Turn on headlights and bulb uses headlight ground. The light being on all the time is the same as a burnt out bulb right?

[Ken Bowers]

I suggest you remove the "info" fuse that will deactivate the Onstar. It is in the under hood box near the steering column.

My theory is that the onstar causes low system voltage that leads to many problems.