help finding the main vacuum hose

[JON3ZI]

hey guys, I'm currently having trouble finding the main vacuum hose on my 1990 VN SS, so i can finish up installing my gauge if anyone could send me in the right direction would be muchly appreciated.

[328FTW]

Main vacuum? If you mean to the MAP sensor then it's mounted on the rear firewall on the passenger side and you can T into that line for a reading. Any feed behind the throttle body will do though, there are a couple capped off nipples near the throttle body that you could use which would work fine. Just pull the cap off and shove the correct size hose onto it.