Fuel Pump Relay

My wiring diagram showed three wires at the fuel pump. The info I looked at was for a 96 K1500 5.7L engine? I also looked at the partsbook for fuel pump connector, it showed a three wire connector. Maybe there is new style and old style??

i dont know but One ground goes directly to the frame.

It sounds like you have a bad ground oir fuel pump control module. Here are the fuel pump wiring diagrams and a guide to help you check the wiring and connections.

https://www.2carpros.com/articles/how-to-check-wiring

Please let us know what you find. We are interested to see what it is.

I got a new fuel pump balance module fix the problem cost $54.00 Thank you so much

i own a 1996 chevy 3500 HD tow truck ,vortec 454 ,4l80e trans. well it keeps on burning up fuel pump relays ,what could be making it do this

most likely a bad ground.

I have a Chevy 1500 and Since the end of May, I have replaced my fuel pump 3 times. I have also replaced the sending unit, wiring harness, fuel filter, 2 o2 sensors, the idle air intake valve, alternator, and fuel relay. After I replace the fuel pump, the truck runs great for about a wekk, then the check engine light comes, then about a week later, the engine dies and I have no fuel pressure and no power to the pump. What else should I check/replace to fix this issue?

[quote:7bb25bc3aa="rdcjb"]Engine Performance problem
1996 Chevy Truck 4 cyl Two Wheel Drive Automatic 100000 miles
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I have a Chevy 1500 and Since the end of May, I have replaced my fuel pump 3 times. I have also replaced the sending unit, wiring harness, fuel filter, 2 o2 sensors, the idle air intake valve, alternator, and fuel relay. After I replace the fuel pump, the truck runs great for about a wekk, then the check engine light comes, then about a week later, the engine dies and I have no fuel pressure and no power to the pump. What else should I check/replace to fix this issue?[/quote:7bb25bc3aa]

My fuel pump on my 97 s10 went out recently it was an electrical problem that caused mine to go out. They also had to change a map sensor and the crank shaft sensor on it. Don't know if that will help.

Have you cleaned out the tank? There may be water or dirt clogging the pick-up filter in the tank. If the punp can't get fuel out it can burn out or may just not be able to pump since it can't pick up fuel. Is the pressure at the rail zero or does it have a low reading. I've had 2 pumps replaced in 200,000 miles. They seem to last about 100,000.

Other Category problem
1996 Chevy Truck V8 Two Wheel Drive Automatic 332k miles
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i just lost my fuel pump and put a new one in and it works fine but my truck wont satr ive checked for fuel pressure and spark and have plenty of both. i also checked the relay and its good too. im trying to chase down the cause of the no start any suggestions? thanks

P.s i dont know if the pcm might be on the way out with the miles it has on it?

If you have spark and fuel then check the gap of the spark plugs. If your computer is bad then there would not be any spark and/or fuel. I would test the ignition module considering the miles. Autozone or a place like that will do this for free.
Is the check engine light on?

no check engine light

i also want to try an injector pulse width test because i know i have fuel up there its acting like the injectors arent spraying but the trucks been maintained and i just put injector cleaner in it

After changing the fuel pump on my 1996 Chevy Silverado, and changing the fuel pump relay, it still doesn't work. Someone told me that the ignition control module could be the problem. Is it possible that the control module will keep the fuel pump from working? If not, what else could it be?

Did you verify that there was power to the pump before you changed it?

I have a 1997 Chevy 3/4 ton 4x4 automatic truck. The fuel pump relay is getting extremely hot. Checked the frame ground for the fuel pump and it is seems in good order. Replaced the relay with same results. Replaced the fuel pump with the same results. Removed the underhood relay box from weather box and found the gray wire has actually started melting. The wire goes to the fuel pump. Replaced the ground wire on the battery and cleaned all the contact surfaces. No recent repairs, truck has been wrecked and rebuilt. Truck is also high miles. Only OBDII code is an ignition misfire code that has been there for the 3 years I've owned the truck. Another thing that bothers me is the volt meter only reads about 12.5 volts, with a new battery. Haven't had the alternator checked yet but have a feeling it is do to a short in the system. Running out of things to try. Hoping someone might have some advice. Aprreciate any help.

Will try the oil pressure switch. It is a 5.7 with a 4L80E automatic transmission.

The computer energizes the fuel pump relay by grounding one side of the coil in the relay. You need to check the fuel pressure, don't let the pump fool you because its coming On-it might be inadequate pressure. Also look below this how your fuel system is wired

www. .com

95 chevy 1/2 ton.with a jumper wire in the relay i checked fuel pressure there is lots.there is no 12volt signal coming when the key is in the crank or run position at the relay to energize the relay .it does have battery power at relay. it also seems like there is no signal going to the injectors either.there is no fuel coming out when cranked .

Since you know how to jumper a relay find me some spark at the pug wire and report back your findings. Don't have sparky we are not gonna have injector/s pulses. That's Y she's not starting No fuel in the combustion chamber.

i checked ignition and there was no spark.i checked fuse panel under the hood on fender well and found that ecm-1 fuse had no power.i supplyed power to it,truck started and my dash warning lights where working.where should i start looking for the open circuit.

found that ecm-1 fuse had no power.i supplyed power to it

The power to the ECM-1 fuse comes from the ignition switch. The only time it has power is when key is at On or Start position.

1997 Chevy Truck

Is the fuel pump supposed too kick in everytime u turn the key on if so what would cause it not to.I replaced the relay.I'm having to prime engine to start after it sets overnight.fuel pump only kicks in maybe 2 out of 5 times.

thanks i found the problem. the contact in the key switch was burnt.

Yes, it's supposed to energize for 2 seconds when the key is turned on. If it's not doing that, then you could have a problem with the fuel pump relay. This truck can run without a relay after a long crank because it has a redundant fuel pump power supply through the oil pressure switch.

I would need the model and engine size to check the wiring diagram to make sure they share the same fuse.

Engine 5.7 and 1500 series

Yes, one fuse feeds both the relay and the oil pressure switch so that is not your problem.

So I could have a faulty relay or what should I check ?

Yes, I gave you the diagram so you could test the circuit but the relay is very likely.

Replaced fuel relay and still can't get fuel pump to kick in every time I cycle key any suggestions?

Yes, test the circuit as I advised the first time, I gave you the wiring diagram.

Hi just got the truck last week
and even my insurance agent was impressed
it was a 1 owner and only has 101,000
(350 or 5.7 with OD auto trans)

ok anyway which leads to my problem
i just put a cat back system in it
and while under the truck i could hear the fuel pump humming away key off and not even in the ignition

i was thinking fuel pump relay possibly stuck?
but i cant seem to find it
i went back to the prior owner
he's trying to find the owners manual for me
(their in their 60's and seems the Mrs. took it out to read and never put it back)

all help would be greatly appreciated, Thank U all ,,, signed Joe M.

It should be on the passenger side on firewall next to blower motor. At least that is where mine is on my 89 chevy

How many gas tanks do you have? With one gas tank only one relay that I know of. Could be an oil pressure switch in parallel with the relay. It's a redundant power supply to the pump, the switch and relay should have no effect on each other.

Electrical problem
1990 Chevy Truck V8 Two Wheel Drive Manual

Have a 1990 3500 chevy truck. Fuel pump runs with key off. It will shut off after 5-10 minutes. Misses while idling. Have check relay and fuse. Both good. Where is fuel pump oil pressure switch and could a faulty one be causing this?

I dont know what you meen by fuel pump oil pressure switch. The electric pump will have a fuel pressure switch built in. Have you checked the ignitioon switch and ignition relays.

Oil pressure switch is located behind distr . Unhooked it and fuel pump shuts off. Put new one on and pump is doing same thing. Showed high oil pressure all the time, then when I unplugged it it showed hi pressure at start up and then none when key off. With new switch, it shows 60 lb at start up and bleeds down to half way when key shut off. Also check gauges lite is coming on with new switch.

If your check guages lite is coming on it will store fault codes in the computer. You can pick up a scanner for about $30. That will help you pinpoint the problem more accurately.

[Computer will not store codes as I have to unhook bat cable for pump to shut off. Replaced ignition switch and it is still doing it. When I unhook ing switch the pump runs right. Help

Wow thats a weird one. Did you ever have any wiring problems in the past, wires melted together or anything like that. Maybe you got a bad switch from the parts store.