Where is the fuel filter located on a 1995 Dodge Ram B3500 Van 5.9L

We are considering buying this vehicle. We figured out how to bypass ignition switch to start it. Now, the motor turns nicely but, won't fire without using quick start and dies immediately. The van sat for several years and we did drain the old fuel out of it and put in fresh and seafoam. Could the filters be clogged? The owner said he replaced the fuel pump just before he parked it. or could it be an electrical problem? There is no sounds coming from the pump at all on start and we're thingkin it may be the relays that are bad. If so where are they located? We found three under the hood at the middle. They are black cubes with three prongs. Did we hit paydirt or are they somewhere else?