I used one from 69 barracuda. somehow I think did have the oil wire on the brake light which explains the pulsing. I switched them around,and the brake light is out and I have the pulsing at the sender, but gauge still dead. The wiring diagrams can throw you off as the drawing looks like you are looking straight at the round connector, but it really is from the rear.I'm starting to thing bad oil gauge. I will chase after the fuel gauge next. Its strange though I do not remember taking that round connector apart.
