We have a 2003 Newmar Dutchstar, Freightliner chassis, Cat E-3126, 80,000 miles. In the past we have pulled a loaded three horse trailer over 7,000 ft. passes without a problem. Now we are overheating crossing the Cascades (3,500 ft.). I have drained, flushed and replaced the coolant with proper coolant. Today I removed the side radiator grill, loosened the condensers, treated with de-greaser and pressure washed. That being said, I am concerned that the speed sensor on the hydraulic radiator fan is not increasing the speed when needed. Last trip I pulled into a rest area at the top of a 1,800 ft. climb, temp gauge was about 210 and the fan was not particularly noisy. Where is the sensor and how do I replace it?
