I have read through many posts but haven't ran across my specific issues. I am considering buying a 1992 F250 4x4 351 AT with 60k original miles from the original owner. The truck has two issues that I would like to fix:

1. It runs fine on the rear tank but dies when switched to the front tank The front tank is full of fuel.
2. After sitting for about a week without being run or driven, the battery will drain down to the point that it won't have enough power to start. This does not happen if driven at least every couple of days. I'm wondering if the horn relay could be stuck?

Does anyone have any ideas on either of these issues? Also, any ideas on a fair price for this truck in good condition (no rust, just faded paint). It's a plain Custom with A/C and a vinyl seat.

 

probably front fuel pump is bad, and needs to be replaced. to check for the electrical problem hook a test light betwen the + post and the cable, an start pulling fuses, when the test light goes out, you have found out whch circuit needs to be repaired.