been searching for days just need some help on where the VSS is for a 1999 ford f150 lariat ext. cab. pictures would be great, but a good explaination is fine. I tried installing it without the wire connected but it seemed to lag on the screen a bit. thanks guys for your help ahead of time.

VSS Wire: Passenger’s side engine bulkhead.

VSS Wire Color: Gray/Black

first, sorry for posting in the wrong section. second, what is the bulkhead? thanks for your help