What could cause this? The problem is when i start the car and turn AC on aux fan does its little check and starts spinning. i plug in inpa and switch signals how fast i want to spin it. everything works fine i can go from 10-90% but then when engine gets warm fan stops and wont accept my signals anymore. i can see that dme is still requesting fan to sping up to 15 speeds. this value is rising all the time but fan wont start spinning. Any ideas? i just replaced temp switch at radiator outlet but that didn't fix anything.