Both turn signals come on with Left Signal- replace multi-function switch and still have the issue

[Ronin7]

Hello,

I have a 2002 Suburban 1500 and I am having issues with the turn signals. First symptom was right turn signal would sometimes not work or would come on and off rapidly then just stop. The next symptom was that both signals would come on with the left signal. I replaced the multi-function switch and an still have the same issue. I have a flasher relay on order and will replace that when it comes in but are there any other suggestions?

Thanks-
Nathan

 

[4silverado]

Out of curiosity, are you running LEDs

 

[ORVietVet]

Welcome to the forum from Oregon. I suggest you do a "signature" and put all vehicle info there. Every time you post, the info will be there.

Sounds like either an LED problem, like @4silverado said, or just weird bulb/ground problems or a junction block problem at the p/s rear undercarriage area.

But, the LED's do cause problems like this ALOT.

 

[Ronin7]

The issue with the right turn signal coming off then on then flashing very rapidly (faster than a bulb-out flash) was with standard bulbs. I did switch to LED bulbs when the dual flash started happening but these are LEDs with built-in load resistors.....

 

[99Sierra2500]

Used to have this issue with the brake pedal switch, don't know anymore.

 

[Tonimus]

First, welcome to the forum!

The only LED turn signals that you should use are ones with rectifiers (often listed as non polarity specific) and load resistors. If the light is missing either of those, it can cause all sorts of weird issues.

 

[Ronin7]

I just wanted to give an quick update. I think I had multiple issues going on but yes, using the "error free" led bulbs fixed the hyper flash issue. The other issue I had was the right turn signal was erratic and sometimes would flash very rapidly (faster than the bulb out flash) or not work at all. That issue was fixed with a Diode Dynamics LM487 LED Turn Signal Flasher which was a direct fit for the original flasher (I purchased on Amazon). My OEM flasher was indeed causing the erratic turn right turn signal.

I appreciate all the words of advice and I can now drive the Suburban again without feeling like a total a$$hole for not using my right turn signal!!

 

[AuroraGirl]

I just wanted to give an quick update. I think I had multiple issues going on but yes, using the "error free" led bulbs fixed the hyper flash issue. The other issue I had was the right turn signal was erratic and sometimes would flash very rapidly (faster than the bulb out flash) or not work at all. That issue was fixed with a Diode Dynamics LM487 LED Turn Signal Flasher which was a direct fit for the original flasher (I purchased on Amazon). My OEM flasher was indeed causing the erratic turn right turn signal.

I appreciate all the words of advice and I can now drive the Suburban again without feeling like a total a$$hole for not using my right turn signal!!

The next place to look if it did not fix it would be the multifunction switch. The circuits are actuated through the switch , it’s not quite a “input to bcm” only like gmt900 , and something like voltage on both sides of sidemarker might not seem obvious related but would be multifunction switch

Glad you got it tho