how do I check the fuel pump relay switch for electrical current

relays usually have a wiring schematic on the case of the side of relay. you can follow that to actuate the relay and check resistance or continuity.

This relay is inside the cab, behind the lower trim panel under steering wheel, remove this panel. Now there are two relays there, for the fuel pump, it's the one to the right or closer to the radio!! They do give some problems!! I just changed one awhile back, can't remember if the two will interchange, i just replaced it, if they look exactly alike, swap them and see if that helps. Note, they are fairly small relays as compared to the ones found under hood. Go to NAPA and get the part # listed below, other parts stores are going to sell you the wrong part, or use this number as a crossreference at other stores!!! (NAPA part # ECH AR172)