Connecting a vent fan
First of all, the "neutral" that you listed for the new fan/light is NOT a neutral, it is a ground. The standard colors are:


White = Neutral (you have one in the existing wiring, 2 in the new unit)
Green &amp; bare = Ground (you have bare in the existing wiring, green in the new unit)
The other colors (black &amp; red in the existing wiring, black &amp; blue in the new unit) are all Hot.


1 - Wire nut all White neutrals together. Your existing wiring has one neutral because the fan &amp; light are on the same circuit so they can share neutral.

2 - Wire nut Green &amp; bare ground together.

3 - Wire nut Blacks together for fan switch.

4 - Wire nut Blue to Red for light switch.