What is this device?

[alexanderjda]

This thing is in-line on my 3/8 fuel line coming in from the tank. It has two wires. It seems to be preventing proper fuel flow (maybe) to the fuel pump. It's located toward the front of the truck, about 12 inches before fuel filter.

1984 GMC Sierra Classic 7.4L

I've captured the part number in one of the photo attachments. Thanks!

 

[CheemsK1500]

I can't be sure, but since the black box on top looks like a relay, and it's coming from the fuel tank, I'm going to guess, it is someone's improvised anti-theft device. If it works like I think it does, there is probably a hidden switch somewhere that opens the valve and allows fuel to flow freely. You can either trace the wires, and use it yourself, or just omit it entirely.

 

[newguy11]

It looks like a Solenoid to me when power is applied it should allow flow. Why? No idea. I’m curious to know when power is applied. My guess is that it doesn’t belong.

On another note your battery terminals look like they are arcing. Clean them nice and reassemble tight. Battery clamps do wear out over time .

 

[CheemsK1500]

It looks like a Solenoid to me when power is applied it should allow flow. Why? No idea. I’m curious to know when power is applied. My guess is that it doesn’t belong.

On another note your battery terminals look like they are arcing. Clean them nice and reassemble tight. Battery clamps do wear out over time .

You're right, it does appear to be a solenoid, I had a brain fart and called it a relay. As for purpose, someone likely put it there to fool potential thieves into thinking the truck has engine problems and abandon it, once the carb runs out of fuel.

 

[alexanderjda]

These are great replies, thanks everyone.

 

[SirRobyn0]

You're right, it does appear to be a solenoid, I had a brain fart and called it a relay. As for purpose, someone likely put it there to fool potential thieves into thinking the truck has engine problems and abandon it, once the carb runs out of fuel.

Just checked the PN# that can be read in picture #2. It's listed as a discontinued on off valve manufactured by ASCO. My guess is not for theft purposes, my guess is someone had a hard start issue due to fuel drain back. Rather than fixing the problem they installed this valve and simply wired it to a ley on 12 volt power source. I suppose the way to find out would be to see where the wiring run too.

 

[alexanderjda]

Oh great! I couldnt find that part number. I'm pretty sure that it was put on for theft deterrent. It has power when the key is in on position. I just removed the silly thing. Thanks so much for looking into this.

 

[SirRobyn0]

Oh great! I couldnt find that part number. I'm pretty sure that it was put on for theft deterrent. It has power when the key is in on position. I just removed the silly thing. Thanks so much for looking into this.

It's certainly not factory whatever the purpose was and like you I'd remove it.

 

[oldretiredafguy]

The only thing has proven time and time again for anti theft is a double barrel 12 gauge, or over under 12 gauge, or a single shot 12 gauge, or.....hell, you get the message.

 

[Radiohead]

Hell, even a stick shift is deterrent enough in many cases

 

[CheemsK1500]

Hell, even a stick shift is deterrent enough in many cases

Many 1st gen Ford Super Duty owners beg to differ. The average crackhead jacking cars at knifepoint may struggle with a third pedal, but anyone mechanically inclined enough to start a vehicle without a key, isn't going to be deterred by a marginally more difficult driving experience.

 

[CheemsK1500]

The only thing has proven time and time again for anti theft is a double barrel 12 gauge, or over under 12 gauge, or a single shot 12 gauge, or.....hell, you get the message.

Guard the whole fleet with a Saiga or VEPR.