So, the two middle fan speeds work but the highest and lowest speeds don't work at all. What do you all think? Thanks, Dave
It is possible that the lowest speed is low enough for it to be difficult to determine. I suspect the relay, as the highest speed bypasses the resistors, using the relay to provide maximum voltage to the motor. I would suggest replacing the relay first, but it is easy to test. The relay coil, like any electrical device requires voltage and ground to operate. The resulting magnatic field applies the battery voltage to the motor through the contacts in the relay. Ray
I had the same problem and as Ray said it was the relay. Just take it out you can easily see if it is no good as one of the coils will be broken. You may need a magnifying glass if you are getting middle age eyes.
