blower module

thanks to all for the info.
97 concord atc tested for fault codes found one, 31, rec. door we knew this was bad before we lost the fan speeds.my question now is, is there a blower module,the atc does not look like it can handle blower amps figured there is something else in the circuit.went to purchase a book no one had it in stock so i had to order one.if anyone could post the circuit i would appreciate it.

Yes, there is what is called a "14 Speed Blower Power Module" for cars with ATC, the module receives a signal from the BCM (Body Control module) to adjust the fan speed based on information from the in car sensors and the ATC Head Unit Settings, it is located under the passenger side dash (The panel under the dash has to be removed to gain access to it) and is mounted with 2 screws into the heater box.