Where are the two fuel pumps located on a 1988 ford 350 one ton 6 cycle 300 van?
If believe the there is a low pressure pump in the tank and a high pressure pump close to the fuel filter on the frame close to the transmission.
Since you sias pump(s) in plural, I'm assuming that you have dual tanks. Have a friend put their head by the tank in question and listen, when you turn the key to the "on" position, they will hear a high pitched buzzing if the pump is working. That is for the pump in the tank, the one located under the drivers door however, I do not know.