Gas gauge being optomistic!

[southernspeed]

I've searched till my eyes bled (well...nearly ) and all gauge posts seem to be that they're pegged or won't go over 3/8 or 1/2 tank.
Well...mine goes way over to the right when I fill it up, then starts going down as normal until it hits about the 3/4 mark and just stays there!


Any know about this one?

 

[southernspeed]

ttt anyone?

 

[1985_K5_Silverado]

Has it been this way as long as you've owned the truck, or did it just start happening some time after you bought the vehicle?

(Gauges that aren't reasonably accurate bother the hell out of me)

 

[southernspeed]

Just happened a few days ago! Been perfect for 10 years!

 

[1985_K5_Silverado]

Maybe this page from the '85 GM shop manual will help (and maybe it won't). I believe the tester mentioned thereon is a device that simulates the sending unit's 0-90 ohm resistance range.

 

[muddybuddy]

nope its working properly! after it eats 1/4 tank it turns into a hybrid
thats the secret behind these trucks...shhhh dont tell anyone

 

[1985_K5_Silverado]

nope its working properly! after it eats 1/4 tank it turns into a hybrid
thats the secret behind these trucks...shhhh dont tell anyone

You've discovered the secret! My 8mpg is actually 38mpg. The hard part was converting my starter to do double duty as both a starter and a drive motor. Being a full-size, the huge battery bank fits easily behind the back seat.

 

[longbedder]

Should be between 0-90 ohms, like the gent above said. I fixed mine by making new ground connections from the tanks to the frame, and running new wire to the very back of the guage from the tanks (removing the original wiring and bypassing the printed circuitboard in the dash).

 

[southernspeed]

nope its working properly! after it eats 1/4 tank it turns into a hybrid
thats the secret behind these trucks...shhhh dont tell anyone

Wow that's good news!
Of course.........IF you're wrong, you WILL come and push me home when I run out of gas won't you!
1985_K5_Silverado, thanks for the info.

 

[southernspeed]

I've just disco'd the wiring plug by the tank and turned the ignition on expecting the gauge to go to Empty but it climbed right around WAY past Full. Is this right????