GUIV Fuel gauge has false reading

Quote:

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Originally Posted by threedogs

hopefully the tank is clean and you havent sucked up any gunk,
I transfer fuel well before the light comes on.

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That is a comment that has always puzzled me (not having a shot TD as you see it heaps of times by lots of people)...

The fuel pick up is in the very bottom of the tank in a little surge baffle thingy.
I've always wondered how does running the level of fuel down suck up anything extra over what would have got sucked up anyway... if you get my drift.
The only thing that should get sucked up is any floating gunk or 'lighter than fuel' contaminants such as some of the ethanes.

One would think rust, dirt, grit, scale or particulates etc in the tank will all sink and find their way into the pick up in pretty short order.

Most of us run our Subs to dead empty so why wouldn't it be OK to run the main to the low light.
That is what I have always done on my 4X's

For the fuel gauge to be reading higher the resistance in the fuel gauge circuit needs to reduce (unless the alternator is overcharging.....even then it's not likely). So I can't see it being an earthing, wiring or connector problem.

What I think has happened is, due to the aftermarket fuel tank and the fuel level being so low that the fuel float may have been out of the liquid. This has allowed the fuel float and arm to bounce around excessively and the float may have become stuck on something in the tank.

I would just fill the tank and see if the gauge reads full. If the float is stuck hopefully this dislodges it. Then just drive it and monitor it. You know how many Ks you get out of your main tank so you will be able to tell really quick if the fuel gauge gets stuck at a quarter tank again.

If the gauge is stuck at a quarter tank then you will need to remove the sender unit and check.

Agree with Rodney...
Bad earth is a fault that would extinguish low level light so possibly explains that but then the gauge will read less than actual so doesn't explain that...
Stuck sender explains the gauge but possibly not the low level light

Drop some motion lotion in the sucker and see what happens...

yeah cheers guys, that did cross my mind too to be honest as its just a float so i have filled the tank and will run it to the light comes on as i will have the Sub full next time if it leaves me stranded. Thanks for your help. I will let you know for sure.

Yep also agree with rod..
When my float arm parted ways it read guess what.... 1/4 tank..
I'd be pulling the pic ups out before filling em bloke..
That way you can check earth points to..
(Bugger, just read you have filled em)

Here is an awesome set of pics of your sender, yes its an Ebay listing... (thanks steve coogan whoever you are)
http://www.ebay.com.au/itm/Nissan-Pa...8AAOSw-yxU3AN1

The green thingy is the fuel pick up and sits right on the bottom of the tank.
It can slide (but not easily) up and down so it can be adjusted for different tanks

The silver cylinder thingy on the seperate mounting rod with the yellow wire is the fuel low level light switch
They are a bit of a strange critter on how they work and when there was bugger all fuel maybe it got confused

The other pics are close ups of the wiper arm and resistance strip etc for contents gauge.
Perhaps when it was dead empty the wiper was at a point on the resistance strip it hadn't ever been before so the gauge went to a happy place sama sama as when the float falls off.

http://www.nissanpatrol.com.au/forum...015/11/140.jpg

http://www.nissanpatrol.com.au/forum...015/11/141.jpg

http://www.nissanpatrol.com.au/forum...015/11/142.jpg

http://www.nissanpatrol.com.au/forum...015/11/143.jpg

http://www.nissanpatrol.com.au/forum...015/11/144.jpg

Nice find ET


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