Wiring problems of the 2011 GMC Sierra 2500

We purchased 24 2011 GMC 2500 trucks with omaha utility bodies. About 1 month after putting the units in service we had a failure of the module that operates the rear brake/tail/turn lights. It had no left turn light, and the right turn operated with the turn switch set to left or right. We removed the module (installed by palfleet for the omaha bodies) from another vehicl and installed it on the one with the problem. That corrected that unit. Since that time we have had 6 more units that have failed in a similar manner,but varied lights to include right /left turn and brake lights. With any of these light inoperative, the vehicles are not in compliance with fmvss 108, or any operational standard. Now palfleet wants to sell us new lights to cure the problem. Text of their email follows: bill, in understanding from ken pitts in service and john pannell in our materials department that some of the multiple service body units we installed a few months back have had electrical issues with the rear taillights specifically, we were hoping to provide you with information. In the early stages of the fsa (florida sherriff’s association for the state of florida) bid process for these units that dates back to 2010, we worked up the bid price based on the standard light kit package. Per my understanding for Ford and Dodge trucks the standard (incandescent) type bulb/light works properly. In the case of gm (general motors) trucks, due to a different oem wiring harness and certain electrical amp-draw criteria, the standard/incandescent bulb can sometimes overheat causing failure. The recommended correction is to upgrade the two red turn/stop lights to led which, again per my understanding, withstand the heat buildup caused by the gm harness. We will be glad to send you the replacement red lights if you would like to pursue and any of the circuit boards (if needed) at our cost plus ups shipping. The cost would be as shown: red stop/turn light - $18. 00 circuit board - $49. 00.