Thanks for the input, Kaleb and Jim.
The aux fan runs, but apparently only when the A/C refrigerant pressure rises above 325psi. My hot running problem wasn't at idle, only at speed, and even then, only under load (climbing a mild grade, speeds over 80mph, etc..) when the ambient temperature is over 85 degrees F. I will check to make sure the radiator tubes aren't clogged ahead of the fan clutch, but I'm fairly certain that's not the case. I did drive the car again yesterday, and the temp gauge never rose more than one needle width above 80. I tried grounding both of the single wire sensors in the upper radiator hose outlet on the head, but neither of them made the aux fan run. Am I looking in the wrong place for the sensor that cuts the fan in? There's another sensor mounted in that outlet, but it's a two wire sensor. I'm assuming that's not the correct one. Thanks again! -brian
