I think i need a new fuel sender unit. My issue is i lost all dash lights. When i took apart the dash i had to remove the fuel guage, as im sure you all have. When i put the guage back it said i only had 3/4 of a tank of gas. even though i was positive i had a full tank. after a while of driving thinking my float was stuck the guage would go down. when i stopped to fill up, it only went to 3/4 and stays there. Its acting like the 3/4 mark is full. Do you think its a sender unit problem or something massive when i took apart the dash?
The senders can be rebuilt. Sometimes it's just corrosion, or the float itself is the problem. These are easily replaced. There is a website advertising refurbishing these things, but I doubt that yours isn't anything a good rad shop couldn't handle, as they did in my case, until I figured out that they are very simple devices. The hard part is draining the tank. Your local parts store may have a replacement if necessary, I doubt it's a rare item.
For us Ford folks, we've got two issues with bad gauge readings: 1) the Fueltank sender, 2) the Instrument Voltage Regulator, which is in the dash cluster, attached to the printed circuit film. I don't know about GM cars, but it would be make sense that GM followed the trend. If you've got a manual, check out the Diagrams. It reduces gauge voltage from 12 to 5 VDC. Could also be just a bad ground.
A simple way to test the tank unit is to unplug the gauge wire from it. Ground the wire with the switch on. If the gauge goes to full, the sender is bad. If it stops at 3/4, the gauge or voltage limiter is bad. Most likely, the problem is the gauge if it was working before you went into the dash. On some cars, there is a ground strap from the sender to a part of the body, as the tank usually has rubber cushions on the straps. Might check this, too.
Thank you so much for you help. When i get a chance i will try these. As Norm explained about the film, yea GM went with the film thingy. had to put new copper on some of the lights bc they stopped working unless i wiggled them.
So you get a free light show when you take a bumpy road, huh? Have a gander at this site, they have some tech articles too. http://www.autolumination.com/
