This wire provides a ground for the pump relay through the ECM when the key is first turned on but will lose this ground within about 2 seconds.
The tan/green wire I mentioned is a splice wire that is tied into the trigger wire from the fuel pump relay to the ECM. After that it shuts off, unless the engine is being cranked over by the starter motor. The pump will run initially when the key is first turned on but only for a couple of seconds.
#1989 ford f150 fuel pump driver module location code
(I should have added that pulling the codes might not be a bad idea just in case there is a loss of PIP code this being the signal the TFI module sends to the ECM which then triggers the pump relay based on that signal.) After 3 or 4 seconds of cranking the light should still be on. If the light is on, crank the engine over a bit. Take a test light and connect it to that tan/green wire in the diag. If it does not run then it’s very well could be a faulty pump relay. This could be caused by a faulty TFI ignition module, faulty ECM, etc. This means that for some reason the fuel pump relay is not getting a ground through the ECM. If the truck does run then disconnect the jumper wire. You should hear the pump run and the truck should start if this is a lack of fuel problem. Run a jumper wire from that terminal to ground. There should be a tan wire with a green stripe. Look at the diagnostic connector under the hood where codes are pulled.