extractor fan

[withers]

youve probably heard this before but ,
im replacing the fan in the bathroom and the one ive bought only has 2 wires coming out of it , both brown (12v)and the existing wiring has 3 wires 2reds 1 black , any ideas how 3 go to 2 , or do i have to re-wire , its a low vaultage unit
thanks for any help ....

[sparx]

STOP!
2 Reds & a Black indicates the original fan was a mains voltage unit with timed overrun.
ie one permanent live, one switched line from light plus Neutral.
If so you can't fit a low voltage fan to them without a transformer. please check on original fan voltage and reply b4 connecting fan.