starter solenoid won't last a month.

The discount auto part stores sell a multi purpose solenoid to use as a Ford starter solenoid. They are often not up to the task. If I remember correctly the multi purpose solenoids have 4 posts (2 large 2 small) the correct solenoid for your truck should have 3 (2 large 1 small). I am not entirely certain if this is correct, I haven't messed with 1 in almost 10 years. It may be something to look into. We had the same problem with a 89 ford and finally used a NAPA echland solenoid and it out lasted the truck.

yes on location,sounds like you got a feed back from the starter,check for a bare or burnt wire from solenoid to starter,starter could be bad,you sure you got wires on solenoid right,make sure where it is mounted is clean of oil.rust for a good ground.