I honestly don't think it's the controller since it turns on when the A/C is on and even after I put the temp sensor in boiling water the fans came on. Has something to do with my cooling system to where the radiator is not getting as hot as the engine. I've been emailing with Brian about it and he's been great offering me his advice.
He had asked me to check the temp at the intake near the t-stat housing when the engine got warmed up to make sure the engine gauge is accurate which I did. He also said that I should be reading within a couple of degrees on the radiator of what I'm reading on the engine if the t-stat is open. He said that even if the bottom is clogged, the cold side tank should still read that. If not, there is probably still air in the system. With the IR thermometer and the engine warmed up to about 200-210 I was reading about 190-195 on the intake right behind the t-stat housing and around 160 at the top of the radiator near the top hose. I even moved the temp sensor near the top hose since it should be hotter than the rest but it didn't get hot enough to kick on the fans even after the car got over 210 degrees.
So I'm going to try again today and see if I can get air out of the system. Not real sure if I am doing it correctly. Does the heater have to be on with air actually coming out of the vent or do I just move the temp knob from cold to hot? How long should it take to get all the air out of the system?
1990 Mustang GT
306, typhoon intake, E303, stock heads, 1.6 FMS R.R., 70 T.B., 80mm pmas, 42lb injectors, 255 in-tank fuel pump, adj. billet regulator, MSD dist., coil & 6A box, BBK shorties, o/r x-pipe, spintech mufflers dumped, T-5, 3.55's, e-fan, b&m pro ripper, S-Trim, 396.37hp/398.06trq.