Chevrolet express 2012 van left rear turn signal lamp not working bulbs are ok

There are two sets of fuses for the 2006 express . One under the seat and one in the engine compartment drivers side (a real "nice" location). and two sets of fuses for the brake and turn signal lamps, one in each location. I suspect the 2012 is the same. After you finally get the lid out of the compartment the backside has the fuse locations. took 6 hours to figure this out hope this saves a lot of people time. I would havew checked the owners manual, but I thought I knew where the fuses were. I didnt know that they had two sets for the same lamps? I will check some more on 2012

Here is a video on your 2012, grainy, but understandable. https://www.youtube.com/watch?v=-Trlyk661co This may help

The tail light wiring harness in the cargo area is not protected very well. As a result it may become damaged due to normal wear a tear. This damage can causing some or all of the rear lights to stop working.

After a visit to a local mechanic I was told that the rear light wire harness / wire socket was damaged and needed to be replaced. The price would be $550 to replace both sides!! After a 5 minute search I found replacement parts on ebay for $35 (Dorman 923-015). Installed in about 20 minutes and got it working again perfectly. The assembly is very easy. Saved over $500 in less than a half hour