no posted symptoms
, this makes help near impossible, see why.?
checking a relay is covered in every electrical book ever published.
the best way is in the car , running.
or on a bench.
in the car is best because, it shows you REALITY, of why it works or not here, and why.
lets do a 4 pin relay, SPST.
it has 2 pins for the coil (input)
and 2 for contacts. (a simple switch it is , but a slave)
I'm a jeep nut. can fix any jeep, 92s are pre 93s and are a pain.
The contactor has 2 pins one is power, 12v and other is dead,
by default (open)
so the PCM on the car (EFI system) energizes the coil by placing 12vdc ACROSS the coil, that is correct. this cause the huge magnetic field in side to pull in the contactor (relay action)
so you then see that and check the 2 pins on the contactor.
the input pin is 12vdc keyon, (if not blown fuse)
and the output goes to 12vdc, an the fuel pump spins.
now how does the relay really works, in an efi system.
that depends on the car, year, and model and engine type.
but in general if the PCM thinks spark is bad, or driver wants unflood mode , it will cut the PUMP, (BY DESIGN)
that is called PCM logic,(programmed to do that on all cars, by laws)
most FSM books fail to teach this, its like "you just should know this"
here is your FSM. for free, nice huh.
see wiring. (last pages)
first off what engine?
, the wiring is totally diffr. with engine options.
is your car. rule 1.
all schematics for XJ start on page, 131 PDF page not real.
pdf page 145 is your relay see it.
these schmatics then suck ,in that the dont lay it out buy funciton, like newer cars have.
so takes printing out 3 pages, i this case. see index.
note you now learn about ASD and its rules and logic, (complex)
automatic shut down relay,
that is why I asked for the simptoms, to see if its ASD?
if the ASD is shutting you down or FUSE F2, is bad.
the RED wire to the pump relay will be DEAD/
that is why we never guess. we measure the voltage and find truth.
keep an open mind, some times ,its just a corroded connector.
now read this ASD page.
UP to 8 things (based on any year or options)
can cause the ASD to DROP
tell more get more.
tell the symptoms, and oh boy...
if the ASD never closes, we work that first.
if the ASD closes and the fuel pump never spins, same
if the pump runs and quits after 3 seconds, BAM> work that.