Any new properly operating fuel pump relays available?

[bry]

The last couple fuel pump relays I have purchased brand new from the auto parts stores near my house AutoZone O'Reilly's have not worked properly. The fuel pump runs when I turn on the ignition which according to the attached chart is not the way they're supposed to operate. Does anyone know where to get a brand new fuel pump relay that actually works properly?

[Thomas Perkins]

Got mine from Auto Zone for 54 bucks.Works great.What kind of fuel pump you using? I have a Nissan one.With Weber.You sure the one you first replaced was bad.When mine went bad.It would not start.Inside was burnt up.I took it apart.Put a new one on it and it started right up.That was a few years ago.Lifetime warranty.

Edited February 12, 2025 by Thomas Perkins

[datzenmike]

 

 

28 minutes ago, bry said:

The last couple fuel pump relays I have purchased brand new from the auto parts stores near my house AutoZone O'Reilly's have not worked properly. The fuel pump runs when I turn on the ignition which according to the attached chart is not the way they're supposed to operate. Does anyone know where to get a brand new fuel pump relay that actually works properly?

 

 

I totally agree. It would seem that as long as the alternator OR the oil pressure is normal the fuel pump works. Seems to me that if you have no oil pressure it's not a good idea to have the fuel pump continue to run and keep the engine running. How does that make any sense??? If there is oil pressure it's safe to assume that the engine is running and the fuel pump should be too.

 

I would also think that ignition switch to ON should start the pump, maybe on a timer and if the starter used or if and when the engine starts it keeps the pump ON.

 

Says no oil pressure at the top but at bottom it says failure. Is there some difference???????? I think there are some lines missing and/or something lost in translation.

[bry]

Stock fuel pump and a stock carburetor. So Thomas are you absolutely sure when you turn on your ignition switch .... Do not start your engine... your pump doesn't start clickety clacking or if it's a quiet pump no voltage is going to the pump. When I first got this truck it had a rigged arrangement where the previous owner ran a wire from the battery underneath the vehicle up to a toggle switch inside the cab and then the wire ran down to the pump. I would frequently forget and leave this on and come back later to a running pump or a dead battery. To get by I just shorted those two wires internally in the fuel pump relay so that when I turn the ignition switch on the pump is running. This was always worrisome because I was afraid of dying in a blaze of the gasoline fire if I had an accident. If indeed your fuel pump is not running when the ignition is on and the engine is not running I would like to hear everything about the fuel pump relay you got. Manufacturer model number any thing printed on the actual fuel pump relay and even a picture would be nice. Mike you're right about the oil pressure thing for a lot of people. But for me I wouldn't want that because I'm vigilant about checking the oil level and I've never seen a mechanical oil pump fail. I would not want to be stuck with a non running vehicle because a malfunctioning oil pressure sender or wiring failure.

[powderfinger]

It looks like you have an 86 model year truck. Is it the Z24i? Does the air filter cover have Electro Injection on it? The fuel pump relay and fuel pump are different and are wired different on the two models.

[datzenmike]

10 hours ago, bry said:

Stock fuel pump and a stock carburetor. So Thomas are you absolutely sure when you turn on your ignition switch .... Do not start your engine... your pump doesn't start clickety clacking or if it's a quiet pump no voltage is going to the pump. When I first got this truck it had a rigged arrangement where the previous owner ran a wire from the battery underneath the vehicle up to a toggle switch inside the cab and then the wire ran down to the pump. I would frequently forget and leave this on and come back later to a running pump or a dead battery. To get by I just shorted those two wires internally in the fuel pump relay so that when I turn the ignition switch on the pump is running. This was always worrisome because I was afraid of dying in a blaze of the gasoline fire if I had an accident. If indeed your fuel pump is not running when the ignition is on and the engine is not running I would like to hear everything about the fuel pump relay you got. Manufacturer model number any thing printed on the actual fuel pump relay and even a picture would be nice. Mike you're right about the oil pressure thing for a lot of people. But for me I wouldn't want that because I'm vigilant about checking the oil level and I've never seen a mechanical oil pump fail. I would not want to be stuck with a non running vehicle because a malfunctioning oil pressure sender or wiring failure.

 

This is why I said a timer. Comes on with the ignition but will shut off if the engine isn't started. Starter would turn on and oil pressure/charging alternator would hold it on. But that diagram doesn't support this. I put Z24, dash and wiring harness in my 620 and remember hearing the pump come on with the ignition but it was a mish mash of parts.

[Thomas Perkins]

The Auto Zone fuel pump relay I use is Duralast Relay 20550.It is quiet.

[bry]

The Duralast Relay 20550 what I bought from AutoZone and when I turned on the ignition the pump would run. I returned it thinking it was defective.  Based on what Thomas saying I now think maybe some previous owner did some wire butchering to the truck. 

[Thomas Perkins]

Believe it or not.If you were to cross up your  fuel hoses on your fuel pump.It could cause your fuel pump relay to burn up.You know how I know. Cause I did it.I put the fuel line coming from the fuel filter on the top fuel out let on the fuel pump and the other fuel line on the bottom of the fuel pump.I just wasn't paying attention,mind not on task as you can call it.That is why I have this Auto Zone Fuel pump relay.Shit happens.A almost 60 bucks mistake.I took the relay apart and sure enough,It was toasted.

Edited February 13, 2025 by Thomas Perkins

[NC85ST]

Like Mike said, when you turn the switch to the on position, the fuel pump will run for a few seconds and then turn off, if you’re not, at least, trying to start it. Whether you hear the pump or not depends on how noisy the pump is or how good your hearing is.

[datzenmike]

The fuel pump relay look identical to the delayed wiper amplifier or the interior light delay shut off so it has, or could have, a built in delay holding power to the fuel pump for 10??? seconds, more? less? If the starter engages the timer resets to 10? seconds. If the engine starts then the oil pressure should hold the relay on. I don't know why the alternator is involved. A failed alternator would disable an otherwise running truck to get you home. Got to figure lack of oil pressure should definitely prevent you from starting the truck.

 

I wonder if mistakes on that diagram were made?