1989 244 167K

I posted last week (click here to read that post*) that the mainpump on this car was noisy. I had replaced the intank pump last year (less than 3000 miles since then). I replaced the fuelpressure regulator in an effort to solve the noise problem and then today following the advice of the Brickboard I checked the return line for restriction. No restriction and the noise continued.

Further checking indicates the new intank pump has failed. Removing fuse #4 and applying 12v to the left side connector on 4 runs the mainpump as it should but 12v to the right side does not run the intank pump although it supplies the 12v to the connector in the trunk (12v on red/yellow wire). I tried adding an auxilary ground to the top of the sending unit (while supplying 12v to the intank pump +) and that didn't cause the pump to run either.

Question #1 Where does the intank pump get it ground?

Question#2 Based on the evidence does it appear the new intank pump has failed?

*the original post makes it sound like the prepump never worked based on the noise, that is not true; the noise started some time after the prepump replacement. 20/20 hindsight would indicate that was when the new pump failed. It is a ScanTech from FCP Groton; anybody else have a bad experience with these pumps?

Randy