1995 silverrado fuel pump relay

What engine ? could have 3.1 or 3.8 L No resistor ? for what ?
Noticed no Speed Cont. fuel pump relay. What are you talking about . Are you talking about no control for the fuel pump relay from the PCM/ECM engine computer ? The PCM Energizes the fuel pump relay for two seconds when key is first turned on . Two second prime of fuel system . When cranking the engine the PCM/ECM will only energize the fuel pump relay if it see's an input from the crank sensor .

WHAT ENGINE ?????? 4, 5.2 or 5.9 Liters?
Fuses are First, always for ever. on electrics or EFI.
dry rail cranking ! you must crank it.
(if you have liking injector or leaking regulator it can drop fast ,so crank on) yes, 2 men or 1 and small boy, LOL
so check voltage at the pump cranking. please stop guessing.!

the ECU commands up the PUMP , cranking or running
so crank and read voltages at pump or at FP relay.

pump activating, is by premissives. not just a key on event
due to crash and burn rules. (unlike on TV)
same with injection. (spark must be good)
first , buy your self a voltmeter (DMM/DVM) its a very easy tool to use
and on volts, mode, totally harmless to you or car. !!!

be aware, that on some cars
if there is no spark, there is no fuel pumping
or it might take a second to detect no spark and the pump is cut
or on one of my cars the pump works the engine starts for 1second
and the ECU sees no spark (dead tachometer ) even though spark is
good the ECU sees no spark and ALL fuel is cut, injectors and fuel pump relay ( you never monitored the action of the relay?. and its dead.? i bet?) spark monitoring can fail with good spark, !!!
the path, on all cars.............. pins and colors change to confuse...
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the FUEL pump relay is in the PDC
it has 4 pins, its just a 4 pin std, relay.
a coil and a contactor
if the coil is not HOT (12v across the coil) cranking
there will never ever be pump action.
so the first test is to check the PUMP relay coil wires.
the coil hot side is 12vdc key on
the other wire, marked. C20 DB (dark blue?)
it is 12v keyon
and when you crank the PCM grounds this wire and it must go
to 0v, (0.5v max) if not the PCM is in CUT FUEL MODE.
99.999999% sure, its not a bad PCM. see?
if this line dont go low you must find out why the PCM is in cut fuel.
this is pretty easy,its called a scan tool. got one
they only cost $9 (ask)
if the coil is hot at C18 relay pin and 0v at C20
this state the Relay is energized.
so we check pins C16 and 17,of said relay
we check C16 first. its 12v even key off, hot at all times if not, the fuse is blown. (or battery totally dead)
then crank and pin C17 goes hot(note my order of testing, its not random) C17 dead, is bad relay, C17 12v, cranking is dead pump.

C17 is DG/wht wire, (darkgreen.with white stripe?)
if this wire is cut the pump is dead
so is the pump dead, if hot this wire is, and the pump ground wire is cut.
when i say cut that means cut or corrosion,etc.
eg; gross resistance in the path.

takes 4min to show, and longer to type this...
the G305 pump ground black must not be bad. (12v on black wire is just that while cranking)

i will not fully cover PCM permissive on the pump.
but will do so in short.
1: ECU sees spark loss, for any reason.. even when good real.
All ECu do this differently. many read the spark coil primary
wires of inductive (EMF) kickback , on one or all coils.
other cars its just the tachometer signal dead.
2: CMP errors (cam sensor)
3: CKP errors. (crank sensor)
4: TPS stuck at WOT , usually only cuts injectors.. (unflood mode)


ive built and programmed PCMs from scratch and am aware of all pitfalls here. am.
if have the drawings, ask.
or log in to Alldata.com

again, connect the $9 scan tool
keyon
crank for 5 seconds. (min) max 15)
does RPM roll from 0 to near 300? no? bingo.
does DTC 340 or 350 store as you crank or release key
and do not turn off key, wait 1 second, see if DTCs are stored
in the PCM looking with any scan tool made..
if yes, BINGO !!!!

there cud be a module-those cars are complex--send issue to [email protected] a master on any make and model

There is a red and white wire feeding the fuel pump relay from a 30 amp fuse. Both the shutdown relay and the fuel pump relay are grounded by the PCM, so if the fuel pump relay is grounded it should be "on" and providing a direct link from the pump to that fuse.
You should have battery voltage on that 30 amp wire before the relay and then on the dark green and black wire going to the pump.
If you don't have battery voltage coming from the 30 amp fuse, the problem could be before the fuse.
That 30 amp fuse is hot all the time, so it is powered by a fuseable link coming off the battery.

your doing the tests wrong (best I can tell)
most cars for sure USA.
the pump only runs key on for 1 or 3 seconds,called the injector PRIMING state. (keyed on only not cranked) and then....
and for sure the same relay closes full time , cranking or running.
so on dead engine all techs know this and crank at the same time measure the 2 power pins to the pump.
in your case it fails. I bet but that is the only test here.
next is the relay, most have 4 pins as yours does.
.
the PCM energizes the relay pump if you crank the starter
I can only assume cranking works all good?????
these rules in the PCM prevents crash and burn, like Ms Heche(RIP). did.
crash ,engine stalls and pump goes off line and not a huge fire. from broken fuel lines, and is USA law too this. safety
on some cars fuel relay goes off one if spark is lost and for sure injectors are shut down spark seen dead. all this is pure PCM logic. deep inside..
all this is covered in ASE classes to techs. how all this works
it's home users (DIY guys that do no know this ) so here is my lil' hints. late.
it does not work like say a swimming pool pump.sorry
2.2L engine.
oops this 2.2 L puppy has oil pressure switch that kills the pump fast after a short run of he engine, saving it.

all fuses must be good, top PCM too, f9/10
and check engine light good must glow key on or PCM is dead

the ecu enables fuel pump relay first. then oil pressure good susains the fuel pump relay.
so PCM F6 dark green/white wire is what energizes the FP relay coil.
if pump is dead (voltage dead) to pump cranking , no longer than 10seonds(not overheating starter)
and fall fuses are good. all as in ALL.
F6 wire at ECU/PCM is check next or at FP relay.
check all pins of FP relay for correct voltage cranked (dead engine STARTER Good)
and be fully aware of all ways the PCU will shut down the FP relay
not saying I know them all , it is Firmware logic in the PCM.

better photo here.

https://imgur.com/a/rB4j125

You can usually go by the wire colors. The fuel pump relay wires are pink, gray, black, and green with a white stripe. When troubleshooting a fuel pump that is not coming on, the relay is the best place to figure out why. You can pull the relay out and put a jumper wire from the battery to the terminal with the gray wire. If the pump runs, you know that isn't the problem. Then turn the key on and use a jumper between the terminals with the pink and gray wires. If this turns the pump on, you know the ignition switch is sending power to the relay, and the fuse is good. Pull that jumper out, but leave the key on. Push the relay back into the socket, but put a jumper from a ground point to the terminal with the black wire. If that turns the pump on, the ground wire is bad. If not, the PCM is not turning the relay on. Reasons for that may be a bad wire from the PCM, a passlock issue, or the PCM fuse/power wire.

The fuel pump relay should have a schematic on it so you can check it with an ohm meter for a short. If it checks ok and when you turn the key on, you do not hear the pump then replace the pump

the fuel pump relay is on passenger side front fender second one from the left facing engine. THERE IS 4 WIRES COMING FROM IT, Orange, dark green with a white stripe, Black with a white stripe and gray. the fuse is on the inside fuse box it is listed as ECM-B FUSE.

im not sure of the color wires that should be powered but have you checked the fuel pump relay under the hood? also check that you have a good ground at the pump dont check just the positive voltage check for negative (ground) also

The Power Numbers are Correct. Just replace the Relay and you should be just Fine.