2009 GMC Sierra Headlamp/blinker help!

09gmcohio · December 6, 2014

Hello,

My name is Cory, I have a 2009 GMC Sierra 1500 All-Terrain Package. I purchased this truck 1 year ago and this is my first gm or american made vehicle. I absolutely love this thing and i am desperate for some help. I have a "fast blinker/side marker light issue"

First I'm new to this board, I understand that a lot of people post dumb fast blinker questions on here all the time. I have searched the internet and every board i can find. i cannot find a solution.

Second, I love working on cars and i absolutely refuse to take my vehicle to any dealer or shop. Theres no reason i can't handle this myself

Heres my prob,

All of sudden my left turn signal starting fast blinking like there was a bulb out. It blinks 2 or 3 blinks at normal speed then turns into fast mode.

I have LED Taillights (came with truck) so first thing i did was take out the front headlight and replace all blinker bulbs

I replaced the 2 closer to the grill 3157 as well as the 194 small on the side.

I never really checked which bulb actually burnt out, i just planned on replacing every bulb.

I started by replacing both 3157 , i replaced and tested before putting headlight in.

Then i replaced the outside small bulb, I tested and the small 194 bulb worked but for some reason one of the 3157 bulbs stopped working.

I take out the small 194 bulb and test and now both blinkers work

Im so confused, the small 194 doesn't even blink, how could it cause a fast blinker?

The connectors,wiring, housing all look normal, no water leaks or any sign of a problem.

Ive searched and searched the internet before i decided to post this, I'm desperate and would really appreciate any ideas......

I've herd its my multifunction switch, flasher module, turn signal lever

thanks for your time.

Doug_Scott · December 8, 2014

Does this give access to more than one make/model? If so $27/yr sounds like a good deal.

I was wondering the same thing, and after looking at their site, the DIY version (the one for $26.95/yr) is for one vehicle only. It costs an additional $16.95/yr for each additional vehicle. If you look at it as a monthly service, $2.25/month for one vehicle is very cheap. For two vehicles it is $3.66/month. They will let you change the vehicle once during the year, or once during the 5 year plan. They have thought out and made their policies very restrictive in regards to trying to get coverage for more than one vehicle, without paying something.

Not having seen it, I also wonder if it is purely online data, or is it downloadable in pdf format.

Doug_Scott · December 6, 2014

Normally I would say to double check all the sockets, and the wiring connections at each bulb, and at each connector plus. Look for green crap at the connections.

After hearing a friend tell me about his signals acting up, he found that most said it was the flasher. That made no sense to him, or me as well after he called to talk about it. Did some digging and found a wiring diagram at the local auto-electric garage. We saw that the flasher circuit is nothing like the old days, for one thing, it had about 7 or 8 wires instead of the 2 wires that we knew about. He changed the flasher, and that fixed his issue. The flasher is not cheap, ran something like $115.

Do you have any LED bulb in the system now? LED bulbs can create some interesting light shows occasionally.

09gmcohio · December 7, 2014

No I don't have a manual.

Could someone recommend where to get a real factory service manual and approiate scan tool to go with it? It's hard to tell what is what.

I have no LED bulbs. My inside two blinkers are factory 3157 bulbs. Outer light is factory 194. I even Tryed two brands from local auto parts store.

The Truck did have a cheap looking $39.99 hid kit which worked perfectly. I removed the hid kit 3 months before having this issue. It was just plugged into the low beam only, factory harness is in perfect condition.

I suppose it could have had led lights on it and removed before I bought it? Could that cause this. Other then irregular flashing , do led cause any other issues?

I will get the scan tool and manual.

Thank you.

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