Fuel Station Pump Question

[Gunny]

I went to pump some fuel out of the trailers fuel station the other day. I pushed on the power switch twice, it clicked & then nothing.

So after doing some research, I removed the pump & sanded down the gears. When I hook it up to a battery, the pump works like a charm.

So, I go to put the pump back in the trailer & decide to see if the pump works when connected to the hot & ground wire going into the KIB potted module. Nothing ?? I connect a volt meter to the ground wire & the main hot wire going into the plug, & I get 12v. But when I hook the pump up to those two wires, nothing ??

So I call KIB thinking the module is bad, but anyone who can help me was out of the office.

If I was to get the module from KIB, they run between $40 & $50 ... if that is the issue ??

So, thinking about this, why can't I just wire in the pump to a 12v source with a regular rocker switch ?? And I'll wire in the fuel gauge at some point, since I'm getting ready to leave on my first trip.




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[sundancer 87]

I suppose you could wire in a switch to make the fuel pump work. I believe the KIB module has a timer in it so you would be by passing it.


Could you post a pic of the module?

[Gunny]

Here's a photo of the module.

Also, I'm not 100% sure this is the issue thou, and I would hate to spend $50 and the system still not work. BTW, I also checked the fuse & even changed it out, so that's not the issue.

I'm sure this 5 minute timer is so a guy doesn't overheat or burn the pump motor up, but since I only have one ATV, I really doubt I would have the pump on for than a minute or so.


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[sundancer 87]

Yep, says it's a five minute timer right there. If I had to guess, inside the pot is an LM555 8 pin chip. A very common timer module but hardly worth 50 duckies.


If one wanted to a 5 minute timer could be built with the LM555, a resistor, and a small 12 volt relay. Three dollars worth of parts without the pot.


I don't know the real reason for the timer, perhaps like you said not to burn the pump but the pump should be self cooled by the gasoline passing through it.


The timer needs a trigger, a signal to activate the timer. Usually a ground signal is sent to the LM555 to start the time. That signal may come from the second click of the Off/On switch. The switch might be your problem rather than the timer module.


I'd put your meter on the switch and check its function before I'd replace the module as the 555 is a hearty chip and rarely dies.

[Gunny]

Thanks Sundancer ... that's one thing I didn't check was the continuity of the switch. I'll give that a try.

HOWEVER ... I'm also gonna pick up a regular rocker switch just in case ... it just irks me that the system is so "Touchy" instead of simple ... like making the pump gears out of a material that gasoline causes them to swell & that makes the gears stick inside the pump.




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[sundancer 87]

Ah Gunny, if we only had the answers...................

[Gunny]

Originally Posted by sundancer 87

Ah Gunny, if we only had the answers...................

WAIT !! ... WHAT ?? .... We don't have all the answers ?? ........... never mind, I forgot, I'm not a teenager any longer ....

Well, I got a regular rocker switch wired in today & I can pump gas again !! And the fuel gauge never worked with the original wiring set up, but it works great now ... however, when it works, it keeps reading the fuel level even when the pump is turned off. So now I just have to figure out how to have the fuel gauge not draw any power when I turn the pump off.



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[calewjohnson]

Originally Posted by Gunny

WAIT !! ... WHAT ?? .... We don't have all the answers ?? ........... never mind, I forgot, I'm not a teenager any longer ....

Well, I got a regular rocker switch wired in today & I can pump gas again !! And the fuel gauge never worked with the original wiring set up, but it works great now ... however, when it works, it keeps reading the fuel level even when the pump is turned off. So now I just have to figure out how to have the fuel gauge not draw any power when I turn the pump off.



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Find a plunger switch, so everything turns on when the door is open and removes all power when the door is closed.

Cale

[Thom]

Gunny, there is an old saying about gages when you turn off power;
A/C gages lie, DC gages die...... Meaning one type will fall back to zero, while the other type will show last reading when power was removed. That might be what you are seeing.

Disclaimer: it has been 40+ years since I used that saying, so I might have it back asswards.......

Havent had the opportunity to put fuel in my tanks so I dont know how these work.

[sundancer 87]

Originally Posted by Gunny

WAIT !! ... WHAT ?? .... We don't have all the answers ?? ........... never mind, I forgot, I'm not a teenager any longer ....

Well, I got a regular rocker switch wired in today & I can pump gas again !! And the fuel gauge never worked with the original wiring set up, but it works great now ... however, when it works, it keeps reading the fuel level even when the pump is turned off. So now I just have to figure out how to have the fuel gauge not draw any power when I turn the pump off.

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In case you don't know, a fuel gauge has positive power on one side and the other side is grounded (negative) through the float rheostat, that's what makes the needle change position.

That aside, what may have happened is the float/rheostat side of the gauge was connected to a non switched ground. A simple fix for this would be to add a small 'momentary normally off or open' push button switch somewhere inside the fuel door inline of the ground side of the gauge.

Being the push button is normally open/ there won't be a ground connection to the gauge until you push the button to check fuel level.

Without a schematic of the fuel station circuit this seems to be the quickest solution for you.

[Gunny]

Well, I have everything working & pumping now. Ran a dedicated power wire to the switch, when I flip it on, the "Load" side starts the pump.

Then with the gauge, when I would touch the power wire (with the 5A fuse) to the power side of the switch, & the pink wire (on my gauge) to the load side of the switch, the needle shows how much fuel I have. However, when I turn the pump switch off, the gauge stay on, so for now, I just pull the fuse.

I'll work on it some more when I get back from camping !!

NOW, I have to worry about the height of a couple underpasses I have to go under ... or find an alternate route around them. Man, never had these issues with my older trailer ..... HAHAHAHAHA !!

Hey, Thanks to everyone who helped me out here & gave me some ideas & info to get my fuel pump pumping again !!




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