fuel shutoff valve normally grounded?

[Spulen81]

I was testing my spare fuel shut off solenoid last night and ran accross something I'm not sure about. When you apply 12V it clicks and works correctly. When you remove 12V the terminal post where you attach the wire is grounded. This is probably normal for a solenoid like this but I wanted to see what you guys thought. I don't like to keep non working spares around.

 

[rdkern]

I think that's how it works. It's a coil that pulls a magnet - so it would be close to ground when you test the ohms. The 12V is the controlling item, it's either there with the solenoid open or not there with the solenoid closed.

Check the one in your car - put 12volts and "hear" if it clicks.

 

[tditom]

when the ignition is on, the shut off valve is energized and the plunger is in the up position (inside the body of the solenoid). When power is removed, the plunger falls down and blocks the fuel from entering the high pressure chamber.

The coil resistance would be so low that I think you'd have a difficult time distinguishing it from ground with an ohmmeter, but I've never measured it myself.

 

[Spulen81]

Cool thanks, The terminal does have continuity with ground with no resistance shown on my meter.

 

[weedeater]

yeah, it's just a piece of wire.

 

[Lug_Nut]

Just like the headlight, too.
The test meter puts out a lot less current so the small gauge wire in the solenoid coil (or the headlight filament) is just another conductor and not a resistance. At this microampere current flow from the meter the coil is just a continuity to ground. At a higher current flow the coil winding (or lamp filament) becomes the greatest resistance in the circuit and creates the voltage difference when checking voltage on either side of this resistance.

 

[Powder Hound]

Yes, but a good volt-ohm meter should be able to measure a few ohms resistance to ground, while a test lamp would just light up.