THE HEADLAMP SWITCH IN THE SUBJECT VEHICLES CAN OVER-HEAT AND FAIL RESULTING IN LOSS OF HEAD LAMPS AND POSSIBLY OTHER LIGHTS.DAIMLERCHRYSLER CONDUCTED A SERIES OF TESTS AND DETERMINED THAT THE 3500 SERIES IS PRONE TO GENERATING HEAD LAMP SWITCH TEMPERATURES IN EXCESS OF THE SWITCH LUBRICANT THRESHOLD OF 100 DEGREES CENTIGRADE.WHEN THIS OCCURS, THE LUBRICANT SOLIDIFIES AND ADHERES TO THE SWITCH CONTACH SURFACES INCREASING INTERNAL RESISTANCE AND THERFORE, TEMPERATURE.DAIMLERCHRYSLER INFORMED THE NHTSA THAT IT WOULD INITIATE A RECALL OF 79,3665 MODEL YEAR 1994-1997 DODGE 3500 SERIES RAM TRUCKS ONLY BASED ON ADDITIONAL TESTING FROM WHICH IT DETERMINED THAT THE 1500/2500 SERIES VEHICLES NOMINALLY OPERATE SIGNIFICANTLY BELOW THE TEMPERATURE THRESHOLD OF THE SWITCH LUBRICANT.OWNERS OF 1500/2500 SERIES TRUCKS WERE SENT A NOTIFICATION LETTER ADVISING OF THE PROPER METHODS FOR ADDING AFTERMARKET LIGHTING ACCESSORIES.