I am trying to wire a new Hampton bay exhaust fan model VFB25ACLED1-5 to run on a timer. The fan has a light, night light and fan. I don't care about night light but want the fan and light to run every time some one hits the timer. I ran 12-3 wire to the fan from the switch. How do I wire it up. The 5-10-30 1 hr switch has a black hot wire and red load wire and a green ground wire. When I wired the back wire from panel to the black wire on switch then red wire on switch to black wire running to fan/light the timer doesn't work and the fan runs constantly and won't turn off. At the fan I wired the black wire from switch to the black wire on fan/light and white neutral wire to neutral white wire, ground to ground.

The fan has red wire labeled night light, blue wire labeled light, brown wire labeled Fan, yellow Labeled Common, green labeled ground, black labeled hot.

How should I being wiring it up so the timer and fan function properly?

The 5-10-30 1 hr switch has a black hot wire and red load wire and a green ground wire.

There should also be a white (neutral) wire.

There should also be a white (neutral) wire.

Yes of course there is the white neutral

I ran 12-3 wire to the fan from the switch

Where is the power coming in to, the switch or the fixture?

Where is the power coming in to, the switch or the fixture?
Switch

Connect all the whites (including the white to the timer) together. Connect the black of the timer to the incoming hot black. Connect the red of the timer to the red of your 3-wire cable to the fan/light/night light fixture. At the ceiling connect the white of the 3-wire to the white(s) of the fixture. Connect the red of the 3-wire cable to the blacks (or whatever color the hots are to the fan, light and night light).
If you are not going to switch the fan and light independently you didn't need the 3-wire cable. Cap the black at both ends of the 3-wire cable. If you are not going to use the night light, cap the hot to it also.

If you wish, you could install an additional switch to control the night light.