Can anyone tell me what could be up with my gas gage? I read somewhere to pull wire off sending unit, ground it and turn the key on and if it goes to full sending unit is shot. This I did and it went to full. I replaced sending unit and filled the tank up and now it shows 1/2 tank of gas. Also what mpg should this 68 289 2 brl c4 getting? Thanks for any info.

 

Well, buddy.. I have a very basic understanding of the fundamentals, so take my advice with a grain of salt...


In as far as I understand, you have three elements.. The sending unit, the electrical connection, and the gauge / pcb.

1, The gas tank floats a pointer that moves a .. rheostat? you could have a blockage in the tank stopping it.
2, You could have a wiring problem from the sending unit to the pcb, which to me sounds most likely...
3, You could have a bad gauge (blockage, voltage-to-level ratio; i.e. X volts = 1/2 tank.)..

The first seems very unlikely, and it also seems impossible that you'd have a blockage on the gauge.

Hope that helps, maybe someone smarter will come along.

 

Thank you. I did ground the wire and the gauge shot up to full. I think I am going to pull sending unit back out and check it after I ground it and see what happens. The box my sending unit was damaged from where I bought it because I ordered a lot of stuff and the sender box was inside a larger box that was not damaged. Maybe the thing got bent. Also my old float was missing when I took the old sender out. I should have fished it out. If itever warms back up here in Michigan, I'll get back to work on it. Thank you