i just bought a 2000 Blazer 2 door and when i took it on the test drive everything seemed fine. i brought it home and went over to a buddy;s house when i got there the fuel gauge had not left full. once i got to his house i noticed the gauge would just jump all over the place frome mpty to ful and everywhere in between. need help!

 

This is most often caused by a failing sending unit in the tank.

You can try to run some Chevron Techron Fuel System Treatment Plus through the system to see if that can clean off the sending unit grid, but I doubt it at this point. If you want to try it, get two 20 gallon treatments and dump them in with an almost empty tank. Fill up the tank. Then follow that up with one 20 gallon treatment in the next few tanks of fuel. See if that works.

If not, then you will need to drop the tank to replace the sending unit. It is independently replaceable to the tune of around $70. All of the work is the same as replacing the fuel pump assembly which would include a new fuel level sending unit. Most people just use the trip odometer and fill up every 200 miles or so.

 

this was a recall back a few years ago in 2nd generation blazers
i took mine to the dealership and they put in a new gauge set up