I have a 1997 Ford F250HD XL with a 460 in it. Front tank fuel pump was replaced 3 weeks prior to buying the truck and works fine. As soon as I switch to the rear tank it slowly sputters and cuts off in a few seconds. If I had to guess it's the fuel pump in the rear tank. I have a full tank of gas and it is hooked up electrically. If I switch to the rear tank it shows full of fuel on the gauge. Am I right in believing that I need a new rear fuel pump? Thanks in advance for your advice.