My 2005 accord ex-v6 w/mt cruise control doesn't work at all.
How can I fix this?

 

Is Check Engine Light on? If yes, then obtain code. This may allow some insight to problem.

If not, you will need to find a shop manual for your vehicle. I reviewed my 2003-2007 shop manual and could not find any info on cruise control system. I assume cruise control may have been integrated w/ Throttle Postion Control System. Yours may be same. automanualsource.com is a good source for an OEM emanual. Make sure they have the V6 covered w/ their manual.

good luck

 

In the "Engine Electrical" section is where I see the cruise information.

OP- Can you describe what is going on on more detail? Has it worked before? Was anything recently done to the car before it stopped working?