Fast Flash turn signal

Looking for ideas, I'm going to go trace wires now.

My 2007 Avy is fast flashing the turn signal on the right side, this usually means bad bulb.  I have seen intermittent behavior in the right rear light. Standard bulbs and standard lights.

So far I have replaced all bulbs in both rear tail lights with new bulbs.
Replaced the wiring harness in the right rear tail light.
Fuses seem fine but I could not find a fuse for the flashers.

Any ideas would be great.
Thanks!

Have you checked your front turn signals?

I agree with the above comment, usually the fast flash indicates a front burnt turn signal on the side the is fast flashing.  I found a topic on the forum here about signal issues if the front bulb is not your problem, it may be a flasher module issue.  Here is the other thread topic link,

http://www.chevyavalanchefanclub.com/cafcna/index.php/topic,43361.msg684422.html#msg684422

It's at least a place to start if it is not a front signal bulb.

The front signals seem fine.  The rear top bulb does not always illuminate.  I'll check out the link and will replace all bulbs if need be, annoying issue... 
Is there a flasher module on an 07?  I have not been able to find reference to one at the parts store or google.

Follow that link I posted in my earlier post, read that topic.  It tells you where the flasher module unit is located and there is a link at the end of that topic about what it looks like too.

lazm01 said:

The front signals seem fine.  The rear top bulb does not always illuminate.  I'll check out the link and will replace all bulbs if need be, annoying issue...   
Is there a flasher module on an 07?  I have not been able to find reference to one at the parts store or google.

Click to expand...

If the top bulb doesn't illuminate, you may want to check the block on the frame rail by the spare tire for corrosion.

Looks like that link is for older Trucks, there is no flasher for a 2007.  So far so good, I found a brand new bulb which I had replaced already which was jiggly.  The bulb in the plastic part was moving around.  It looks like I may have replaced a bad bulb with a brand new bad bulb.  Hard to find because I would re-seat the bulbs in the garage and it would work for a while.