Fuel Gauge Issue

[chevyguy8248]

I just installed a new motor on my fuel gauge yesterday and i didnt mark the needle location. (I know im an idiot). Anyway, i filled the truck all the way up and turned it on and i placed the needle on the full mark. Now the gauge never moves, its always on the full mark and when i shut the truck off it goes down to 3/4. Any ideas on how to fix this?

 

[Lordkay972]

I just installed a new motor on my fuel gauge yesterday and i didnt mark the needle location. (I know im an idiot). Anyway, i filled the truck all the way up and turned it on and i placed the needle on the full mark. Now the gauge never moves, its always on the full mark and when i shut the truck off it goes down to 3/4. Any ideas on how to fix this?

How long have you drove it after you filled it up?

 

[chevyguy8248]

How long have you drove it after you filled it up?

80 miles

 

[kennythewelder]

Your fuel gauge sending unit is in the tank. You may need to change it out, or you could have a shorted wire to the gauge from the sending unit. If it shorts to ground, then it will read full no mater how much is in the tank.

 

[chevyguy8248]

Your fuel gauge sending unit is in the tank. You may need to change it out, or you could have a shorted wire to the gauge from the sending unit. If it shorts to ground, then it will read full no mater how much is in the tank.

Its not the sending unit. The gauge read accurately before but it had the hummingbird vibration. To solve this i put a new motor on the gauge but i forgot to mark the gas gauges spot and now it is always on full.

 

[Blasphemy]

Is that the only fix to the "hummingbird vibration" is to replace the gauge itself? I'm having that issue now. Not to mention, my gauge has a case of mistaken identity because I have a 25 gallon tank and the gauge goes from full to empty after only 16 gallons. I'm thinking that its something I have to program into the ecm, but the problem is, I never changed the ecm just the wiring harness.

 

[98_k1500]

Is that the only fix to the "hummingbird vibration"?

No, there is a fix for it without doing that, there is a thread on it here.
http://www.gmt400.com/forum/showthr...Gauge-Needle&highlight=hummingbird+fuel+gauge