When taking a look at the Ecoer Air Handler there is a 5 Tap system with 4 wires that control the CFM Range or Speed of the motor. This is shown below.
When trying to Speed up or slow down the fan speed you will keep in mind 2 laws that govern its control
1. Where the white wire is connected, is where the fan motor's speed follows.
2. All four wires most remain connected, so when choosing where the white wire goes make sure to swap the wire in that Tap Placing with the previous position of the white wire.
An example of this Swap
White was on Tap 2
Yellow was on Tap 5
So to achieve Tao 5 Speed you would switch the White over to the 5 and the Yellow over to 2, which is the white wire's previous location.
As so.