04 3500 TD, Dually, all stock, pulling 14K dump trailer. Noticed no turn and brake lights on the trailer - left side only. No signal in the trailer plug, went to the fuse box - all fuses are OK. Than I checked the TDR forums and concluded that the non-replaceble relay inside the fuse box has failed. The Glenn E. Thomas Dodge dealer in Long Beach has confirmed my suspicion. My only option is a new fuse box, $ 220. 00 plus labor and cost of diagnosys, comes to over $ 500. 00 I have already ordered the parts, but if you guys have a better idea, I sure would love to here it. Anyway, happy trucking!