We have a 2006 dodge ram 3500 When we put our hay trailer on it and hook up the lights everything works except for the left turn signal and brake lights. They work on the truck just not on the trailer. Checked all the fuses cant figure out what is going on. Any ideas would be great. Thanks all

 

Both brake lights? or just the left brake lights? just the brake lights on the trailer? Or The ones on the trailer and truck?
It has to be in the plug or a short in a light on the trailer.. your truck "should" have trailer fuses..

 

The 2006 has a TIPM with no separate fuses for trailer ts & brake lights, You can have the TIPM re-flashed at the dealer but it does not always work..

You might have to install one of these:

http://accessories.etrailer.com/search?w=hd%20modulite

These are handy for testing the bumper plug:

http://www.etrailer.com/Tools/Tow-Ready/TR20117.html

 

It is just the lights on the trailer and we had it plugged in on our 2002 dodge and everything was ok. It was just on the 2006 that there was an issue.