Wierd problem while filling up with gas

you are not supposed to smoke while refueling also - do you do that too?

 

It isn't.

 

I mean the trucks entire electrical system is a potential ignition source, and your betting you have a fully functional pump that will stop when the tank is full and not spew fuel all over the place. If every thing goes right there is little risk, or you could turn the truck off reduce the risk to 0 even if things go wrong. People be dumb though.

 

Maybe filling up with the vehicle still running is not excessively dangerous, but there is a sign on every gas pump in the US that says shut the vehicle off so maybe there's something to this?

This may all just be out of an abundance of caution, I really don't know. But I shut the vehicle off as that's what I was taught to do.

Oh, I also don't run with scissors.

 

However, gasoline liquid will not burn, it needs oxygen to create combustion. It's the vapour that is dangerous. Just think of trying to run your engine waaaaay rich. You have gasoline and spark but not enough oxygen so it won't run. Lean it down with oxygen (air) and away you go. As to the guys smoking while replacing pumps, I have to agree with you. It's either bs or guys completely flouting OSHA requirements. Just my 2 cents.

 

I like what you are saying, but I don't see how turning the vehicle off changes anything. And I'm not telling anyone they should leave it running or not. Your electrical scenario would require an exposed ungrounded/positive wire and contact with a ground source, which are admittedly numerous on a vehicle. But what circuit are you closest to while refueling? The tail lights, maybe? That circuit is hot whether or not the car is on, and the switch under the brake pedal has to be closed to energize anything downstream of it anyway, which will occur when you get back in to put it in gear, regardless of whether or not it was running while fueling.

I addressed static as a result of the fuel pump running in a previous post, as well as hot surface contact by gasoline. I can cite some studies on hot surface gasoline ignition if anyone is interested, we got side tracked with smoking.

I'm generally curious about the perception of this and enjoying the discourse.

 

I don't smoke, but cigarettes do not appear to be competent ignition sources for gasoline, in any form. Though I'd not recommend it, because the open flame from a lighter certainly is.

 

Tail lights, fuel pump, locker(if you have it), an ALWAYS HOT when key is on 7 pin trailer plug, 120ac plug. The brake lights aren't the only ones back there also you have running lights. Also the brake lights don't energize when the key is in the off position. Plus if the switch for the fuel pump doesn't stop when the tank is full a puddle can form under the entire truck in short order, the entire trucks electrical system will be exposed to a cloud of fumes an a single short will light it up. You should just be smart and deenergize the whole system, but people be dumb.

 

Toyota uses negative switching for a lot of circuits. So they're always hot no matter the key position. Hence why people have all these issues changing interior lights.

 

This is the part wear people try to say there just as many hot circuits with the key OFF as ON. People be dumb.

 

Can you prove otherwise? The positive is live no matter what. So a short can happen key on or off.

 

lol dude

 

But where there is smoke, there is fire brother! I just think it is unwise to have any unnecessary ignition source near a vehicle when fueling. But there is no way I am going to fault anyone for leaving their truck running while fueling in -30 degree temps to keep their spouse / child warm.

 

I'm open to being wrong. Just please explain how I am.

 

try to turn the radio on with the key off, there's 1. use your brain to find the rest.

 

I see. Do you know why the radio doesn't turn on? Do you know what a short to ground means?

 

Thats perfect if its a short to ground its impossible for it to spark due to a fault, you should turn your key off when pumping. As short to ground is just a way to switch in this case, there is no way the entire entertainment system is shorted, the parasitic draw would be insane. Try to put the windows down next with the key off next bet thats not getting power either of some reason.

 

Can you explain this a little more to me? Is this a situation where the switch is at the end (grounded) side of the circuit instead of the first thing the ungrounded conductor interacts with (aside from circuit protection)? I am more familiar with structural and appliance wiring, and that situation is a very bad deal in those cases because the appliance is energized even if it is off.

 

You don't understand how our trucks work. The circuits are getting power always. They don't drain because the ground is broken turning them off so there's no drain. But a short creates the ground making the circuit live again.

Most cars the power is cut to turn the circuit off. Ours the ground is broken. This is why so many people have issues doing something as simple as changing interior bulbs and not disconnecting the battery. They ground the still live positive wire and boom you got issues.

I think above explains it. But you can choose to break the power or ground to turn the circuit off. Most turn the positive off toyota picks to turn the negative off.

 

There are some circuits that switch grounds ( more common in ECM control circuits because it is tougher to induce a ground vs. a power )... But a good portion of lamps are switched powers. The only lamps I found that were switched grounds were the visor vanity mirrors... there may be others..