I have a 2000 S10 Blazer 4x4 and the fuel guage is malfucntioning.
I guess its the fuel leveler inside the gas tank.

I was wodnering if this was an expensive/inexpensive fix anbd if it was a difficult task to handle.

Thanks

 

9 times out of 10 it's the sender in the tank. Problem is... The sender is part of the pump and only sold as an assembly. Normally costing close to $300 for the pump/sender. The tank must be dropped to change the pump.

Now with that said, I have been chastized by an ex-member here for recommending that you just blindly remove the tank and replace the pump/sender. If you can, you'll need to find the sender signal wire and check the resistance, but I cannot remember the exact resistance range.

 

join the club of non working fuel guages...I have been doing just fine with my tripometer....set it and forget it!! lol....haven't run out of gas yet..and it's been like 4 months.....

 

Hey Kyle, shame on you for not talking about resistance (LOL).

Anyway here is there is the resistance info I have.

All measurements are in ohms
full = 17 +/- 2.1
half = 40 +/- 4.5
empty = 120 +/- 6.5
the base reading according to GM should be between 1/4 and 1/2 and it should be 90ohms.

That being said GM uses a special gage tester. The part # was J24538-A it probably has a different number now.
Another way to test is by grounding the unit if the guage reads full you have a bad sending unit if it reads empty it is the guage. The wire colors vary so I can't give you any ideas there you should be able to trace them easy enough.

That being said, here is my opinion. Any time you are playing with hot wires on the tank pump is a big no no. I personally would never attempt it. It would be better to remove the battery and drop the tank and go from there. Be carefull when removing the pump from the tank. There is a "special" tool ( J 36608) for it but as long as you are carefull and not banging on it with a screw driver you should be fine. A short story on safety I knew a mechanic who pumped all the fuel out of a tank, dropped the tank, brought it outside and was using a screw driver, the screw driver created a spark and ignited the fumes in the tank causing a not so happy ending.

Moral "SAFETY FIRST"

For all of you who have a guage problem and/or are replacing the pump sending unit. I had heard about the wrong sending unit being installed for example a 14gal unit being installed in a 31gal tank. I just heard this so if anyone knows anything about this any info would be great. My guage reads 1/4 of a tank then drops to empty out of the blue if I shut the blazer off,let it set for a couple of minutes restart and it reads 1/4 again, then it will go to empty again a short time later.

 

On the newer Blazers hte fuel guage sending unit is part of the fuel pump assemble, thus not cheap (250-350). There are 3 or 4 versions of the assemble. The only way to know for certain which version you have is to drop the tank. There is a tag on the fuel pump assemble that has a alpha-numeric code on it. You need that to buy the right part. Call around and see who has each version and what kind of warrenty they offer. GM may be the best, however you will pay for it. Less warrenty, lower quality parts will be on the lower end of cost.


On the older models. The gas guage and pump are seperate and much much much cheaper to replace.



One more thing, start saveing your pennies now, wont be long before the fuel pump goes out, and it will usually take the ICM (ignition control module) with it.

 

WHAT????!!!! you mean you just can't drive around with a broken sending unit??? crap! I was hoping to just keep doing what I was doing because replacing the sending unit was going to be too expensive......now I find out this,,.....bummer..

 

You can keep doing it. Just save your pennies while your doing it. I drove around for almost a year with a broken fuel pressure sending unit.

 

I have this problem onmy 00',but with fuse #3 (cruise) popping constantly,even with cruise module disconnected.I am searching for a wiring diagram to see how these systems are or can be cross connected.