for some reason the fuel gauge has stopped going down at 3/4 of a tank, it doesnt go under that even after I put 200 miles on it. when i went to fill it up the gauge went back up, but after 150 miles again it stopped going down at 3/4 of a tank. is there any way that i can find out wether it is the gauges, the computer or the sender in the tank without paying gm goodwrench $200 bucks just to look at it? I know that if i take it in they will say that it is my custom gauges and wont even want to check anything else. i went in before to get my headlights adjusted and they told me that they couldnt because of the body kit.
GM fuel gauge senders use a resistance value of 0 ohms EMPTY and 90 ohms full.
To check the gauge and narrow things down to the sender
If the sender wire is disconnected the Gauge should read FULL i.e. it's at more than 90 ohms-it's open circuited.
If the sender wire is touched to EARTH the gauge should read EMPTY --0 ohms
With the ignition ON , of course
Purple or Pink is the sender output.
Check also the BLACK earth wire is a good earth/ground.
(GREY is fuel pump power
Hope this helps
ALONT
