red/white wire identification

[dirtyb15]

I recently had to disconnect the fuel bowl heater wire because it was blowing the 22 fuse. If i remember right it was a red/brown wire. While i was unhooking it i noticed another wire that had been unhooked and taped up. It was red/white and exactly the same gauge as the fuel bowl heater wire. I could not figure out what it went to or why it had been unplugged. Any ideas?
thanks!

[Stan96]

here's a picture of it, i forget what that thing is called tho, whatever it's called, people usually unplug the wire and use a pipe plug to fill the hole, just don't tighten too much, the housing breaks easily

[Paul H]

It is the vacuum sensor, to show you when you have a restricted fuel filter

[dirtyb15]

Thanks for the info guys. Wonder why it was unplugged in the first place...