2000 GM Blower Problem

I have a 2000 GM with 29k miles. Recently the blower motor started acting up. It will work intermittently. Either it works fine or does not work at all. I suspect either the EATC or the blower speed switch. I have not found any loose connections. Is there any way to test. Currently its working which makes it difficult to find the issue, but it may just go out suddenly driving down the road. I see where many have had an issue with the speed switch but it seems to always be in conjunction with the high speed still working and none of the lower speeds. I am curious, since I either have all speeds or no speeds at all if it could still be the switch or is it more likely the EATC. Please help if you can.:banghead:

Welcome to Automotive Forums. If the high speed works but nothing else it is the blower motor resistor. If none work it is the switch on the dash or a bad connection at the blower motor. The blower motor is under the dash on the right side (passenger). check the wire going from the resistor to the blower motor. Sometimes the electrical connecton to the motor gets hot and it will cause a bad connection. Also, it is in a positon where a passenger might hit it with a foot. I might add that it could be the blower motor itself.