no power to fuel pump pigtail connector next to gas tank on 1990 Jeep Cherokee

Parked car for 3 months,then wanted to move would not start..turned over very healthy with new battery..will start and runned fine with starting fluid. -fuses ok,new battery,full voltage at relays block -installed new pump relay,have full voltage in and out of it -fuel pump has less than 1000 miles (replaced past summer) -no mechanical malfunction or unusual noises present **only "anything" fuel-related issue is a fuel gauge not working (I left the key ON all day a year ago,gauge will not respond after that, but I was still able to drive car for several months).....I suspect an open ground circuit to pump wiring or some kind of a trigger signal from PCM... ..As to the gauge,I am leaning towards the sending unit... please advice....thanks!..

by in Fort Worth, TX on December 27, 2010
1 answer 2 comments
ANSWER by on December 28, 2010
When the PCM receives a signal from the Crankshaft Position Sensor it grounds the Fuel Pump relay, which in turn powers up the Fuel Pump.If there is no Crank signal, the relay will not energize. As for your gauge, it is likely the sending unit.
COMMENT by on January 31, 2011
is it the crankshaft position sensor whats bad.
COMMENT by on January 31, 2011
thanks for your is this sensor located? do I test it...resistance?..voltage? n.o. condition..n.c. condition?...can I override it so to make sure this is in fact the perpetrator? please advice

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