Gas Gauge Acting Up

[thumping_accord]

Yesterday I got in my car to go to work and I noticed that gas gauge needle was almost at empty. This worries me since I know when I was driving yesterday I had at least half a tank. It also worried me cause I had only 250ish miles on my trip meter (I normally get close to 400 a tank). I was thinking I had a gas leak somewhere but never smelled nor saw any. I drove to work and on the way there my gauge goes up to half, then down to a quarter, then up some, then down... so on and so forth. Today I get in the car its reading empty again, I drive to work and on the way it goes up and down from quarter tank to empty but staying closer to the empty side now. Has anyone else had any experience with this issue? I'm trying to figure out if the gauge itself is going bad or if it is the sending unit. What kind of tests can I do? Thanks in advance!

[F22Chris]

Ground the circuit from the sender, the gauge should raise. Give it power, the gauge should drop. If it doesn't, gauge or wiring is suspect.

It's just a potentiometer, so it might just not be making contact like it used to. Your options (if it's the sender) are replacement, or moving the contact point to a fresh spot on the track.

[thumping_accord]

Thanks I'll try to give this a shot. Will the gas light come on at full ground? Reason I ask is the gauge was reading "empty" and the gas light had not come on. Are the two tied together?

[F22Chris]

Sorry that last post wasn't very helpful!

So the sender unit is a potentiometer that gives the high/low gauge readings based on resistance. So the higher the resistance, the higher the gauge reads, and the lower the resistance - the lower it reads.

So test the power wire on the harness and see if you get 5v. Test the ground for excessive resistance. If it checks out from the harness replace your sender. Don't put 12v to the actual sender. It will ruin the sender.

[thumping_accord]

Thanks for the clarification... I have yet to do the test yet cause I have been busy at home remodeling our kitchen (my wallet has yet to stop crying lol). Just out of curiosity if the sender was going bad, when the gauge reads empty wouldn't the gas light come on? I ask cause its pretty much stays bottomed out for the most part now but the light will never come on. A part of me wants to drive my car until the gas actually gets low enough where the light would come on, but the other part of me doesn't want to run the car out of gas and be stranded lol. If the sender triggers the light as well shouldn't it be coming on or is this not the case? I'm really just asking to try and save a little time cause some idiot (me) decided to screw a subwoofer box (from the inside of the box nonetheless) down to the plastic trunk bottom that I put in from a wagon....