Hello
I was wondering if any could school me on why my 85.5 has two fuel pumps.
I understand the in tank pump is a low pressure(Lift pump) and the frame pump is a high pressure.
I was told that it works off boost pressure, which doesnt make sense to me BUT.
The problem
If I jump across the fuel relay, I can run the low pressure pump, move my wire to another terminal on the plug and run the frame(external) pump
shouldn't they run together, they are on the same hot wire on the wiring diagrams I have found.
ANY Help would be appreciated