Just yesterday, I had replaced my fuel sending/pump unit in my 2000 Blazer. After pulling the old one out, I decided to figure out why after awhile, the fuel gauge becomes erratic. After further inspection, 2 things happen over time with the fuel level sending unit.

1. The little itty bitty electrical fingers that slide over the contact board become worn down which decreases the ability to maintain constant contact with the surface.
If anyone ever remembers the old stereo systems with the slide volume control that gave you static in your audio everytime you changed the volume? Same thing happens here with this. Except your fuel gauge bounces instead.

2. The hole where the arm float attaches to, becomes worn which also helps to pull the fingers away from the board due to play.

Just thought I would like to pass this observation along.

 

Interesting. Did the pump itself poop the bed also?
So if you just keep the tank full all the time so nothing moves it'll last forever!

 

What makes this worse is when you start to get buildup on the surface of the resistor grid. The buildup tends to be abrasive and wears down the "fingers" faster. In the image above, the tip of the "fingers" is gone completely. They should have a rounded tip that bends back up.

 

Your absolutely right Kyle. The tips are much bigger than what you see here in the photo. I should have taken a comparison pic, but it didn't dawn on me until afterwards. I'll drop the tank tomorrow and get some more pics.


oisinirish:
No, you are still going to have liquid movement inside the tank, regardless of how much fluid you have in it.

 

Now that is dedication!

 

I know just being a wisenheimer.

Make sure to photodocument the replacement process this time too.

 

I was going to say... thats a helluva nice case of OCD and Boredom ya got there!


as far as the fuel gauge sending unit not wearing out ever.... Just bolt it in place!
It's like Money right? You Still have checks, you cant be broke... your gas gauge says full, you can't run out!

 

that light that says LOW FUEL, ignore that.
seriously good post, very informative

 

Mine moves up if im goin up a hill or on an uneven grade, and down if im going down hill. Y is this?

 

Just the location of the float in relation to the fuel. Think of a bowl of water with a float attached to a permanent location. Now tip the bowl away from the float mounting point and you'll see a the angle between the mounting point and the float change. It'll help if you pretend that horizontal is a straight line from the edges of the bowl. So as horizontal tips away from the float it appears to the float that the fluid level is rising. Maybe I need to draw this. My English has left the building.