Parks2004Saab93

My blower fan stopped working again. I have previously replaced my fan, fan module and ACC, all of which have failed at some point over the past two years. The ACC was most recently replaced this past winter, and now it appears it has failed again. When I checked the voltage on the brown/orange signal wire at the connector to the module it was not registering any voltage. What is causing the ACC to have repeat failures and is there something I am missing in diagnosing this problem?