Sounds like you need to change the unit itself. Good luck getting to where the 3 lines hook up in the dash. I got to the vacuum line end so I used the one on the new unit but I couldn't get the green one disconnected up in the dash-- the yellow one I couldn't even find where it hooked up. So I carefully disconnected the new cables from the new unit and used the ones already in the car. Vacuum line was the only one I managed to use on the new unit. It all works now.