hey guys. i have a 03 f150 4.6 4x4. auto trans. my question is about my gas gauge. noticed one day that my gas gauge hadnt moved in awhile. stuck on half. itll go down like it should when the keys off. but as soon as the ignition is turned on it shoots right up to half not slow like normal. im pretty sure its the gauge itself thats bad. cuz i unhooked the harness to the fuel pump and sending unit and it still reads half with the key on. unhooked the gauge cluster harness and it drops to empty. and ive done the test on the cluster with the trip button and it reads the correct amount of fuel in the truck. plus when the truck is low on gas the low fuel light still comes on even tho the gauge reads half. so like i said im pretty sure its the gauge thats bad. but i cant find just the gas gauge it self any where. so ill have to buy the whole cluster assembly. and i figured id just swap out the gas gauge from the new one so i dont have to have the new cluster programmed for my truck.so im just looking for some input from you fellers before i go n buy the whole cluster. any help appreciated.

 

I would try to troubleshoot the gauge itself. IIRC they are electromagnetic so there might be some piece of plastic stuck in the needle or something

 

How do you know it isn't the sender that's bad?

The other thing is that when you turn the key on for the first time, the gauge doesn't buffer. Mine shoots right up to whatever the actual reading is; it doesn't move slow. So I think the gauge is likely functioning correctly.

 

It could very well be the sending unit. Becuz I'm no expert. But I just figured that if the sending unit was bad or the float was stuck in the tank then shouldn't the gauge had read empty when I disconnected the sending unit? And as far as the gauge goes, I don't know abot yours. But mine didn't ever shoot right up to what was in the tank. I don't mean it was slow either, but it had a little delay. And also if the sending unit was bad then y would the low fuel light still work but not the gauge itself?

 

There is a gauge sweep function through the trip button test mode, that may reset the gas gauge or atlease let you see what's going on. It should drop all gauges, sweep to max and go back to low IIRC

 

Yea I've tried that too all the gauges sweep except the gas gauge. I was going to mention that earlier but I forgot. So that's another reason I think it might be the gauge. Just wondering if there's anyone out there who might have had this problem or one similar.

 

The only time my gauge doesn't register correctly is if I leave the key on while filling the tank. When I do that, the gauge doesn't move and it takes about 15 minutes of driving before it goes up to Full.

 

Yea I know that's not it. All these fords do that.

 

Yes, the gauge buffers unless you are just starting the truck from the off position.

 

Alright. Here's something different. Don't know if anyone will know but here goes. Just started my job job which is bout 40-45 mins away. Anyway. I have noticed every day n night after driving about 30-35 mins the gas gauge actually starts to work. Every single time after about that amount of time. And if I turn the truck off then turn the ignition back on the gauge will still read right. But If wait about 5 mins it won't. I have no idea what this may be.