91 mustang fuel pump issues

[Shoeman]

I have had this issue with my 93. Sent the computer in for a rebuild and ran great for 3 months and now back to 3.7v to the back swich. Any ideas on what is causing the computer to do this?

 

[General karthief]

I have had this issue with my 93. Sent the computer in for a rebuild and ran great for 3 months and now back to 3.7v to the back swich. Any ideas on what is causing the computer to do this?

this thread has popped up a few times over the years, common problem apparently,
the steps to take to resolve this and similar issues was posted on the first page, the second or third post. There are variables such as swapped harnesses, 4cyl to v8 swaps, auto to stick swaps that complicate things.