Rich4.0L

Howdy, working on a 1990 MJ 4.0 . Fuel pumps work outside but only getting 6.5 volts best I can tell at harness. Learned a lot here all ready and will be checking grounds. One comment above stated a faulty ballast resistor would prevent the fuel pump from kicking on. My understanding was the resistor was not in play during the starting process, only after the engine was running. Was hoping someone could shed some light on this. My problem seems intermittent. Through the harness, with the key the pump in a Jug worked fine. 5 min later nothing. Just found this forum. Probably because even as a farm truck it never stopped b4. Very helpful,good knowledge. Thanks. Rich