While inspecting a malfunctioning blower motor, you find that one of the resistors is defective. Your next step would most likely be to

A. test the switches and relays.

B. check the current draw.

C. check the heater hoses for deterioration.

D. test the evaporator for leaks.

I'd check the current draw first before testing the switches and relays so B is the correct answer.

When trying to diagnose a blower fan motor, there are several components that you should check in the system. First, it is always recommended to check the fuse for power on both ends using a multimeter. You can then proceed to check whether the fan relays and the switches are tested and working. You can test these relays by placing a finger on them and switching the fan’s control on and off.