Fuel Gauge Reads Full Always

[saxtech]

I have a 2003 XLT with 3.0 Flex Fuel and only 43,000 miles.

My fuel gauge is now reading full at all times now. It does not go to empty when I turn the key off and it stays on full when I know it should be at least a quarter of a tank lower.

I'm very concerned that this may be a big repair even though the truck only has 43,000 miles on it. I've only had it 4 months.

Whats going on ? Is this an easy fix, a bad wire to look for, or something more serious ?

Please help.

Thanks everyone.

Gary

 

[97RangerXLT]

you have found the Holy Grail of trucks!! one that never needs gas!

anyways, all levity aside, your cluster is probably the issue, for whatever reason the needle is stuck. you might be able to smack the cluster close to the fuel gauge and free it up, or you may need to take the cluster out and disassemble it...removing the cluster shouldn't be too much of a hassle, just several panels and bezels need to be removed.

Good luck and let us know what you find.

AJ

 

[97RangerXLT]

the other option that might be your issue is the float in the sender unit in the tank might be stuck on top after fill up. take the truck down a bumpy road and see if that fixes it. or take a rubber hammer and whack the fuel tank a few times.

Try this first before messing witht he cluster

AJ

 

[alwaysFlOoReD]

I seem to remember reading about testing fuel gauge. Something like grounding out the gauge would make it read full. Maybe you have a wire shorted to ground.

 

[Dirtman]

I'd check the obvious first, wiring. But in my limited experience, fuel gauge issues on those model years are usually from the anti slosh module. (Back of the cluster).

 

[saxtech]

the other option that might be your issue is the float in the sender unit in the tank might be stuck on top after fill up. take the truck down a bumpy road and see if that fixes it. or take a rubber hammer and whack the fuel tank a few times.

Try this first before messing witht he cluster

AJ

Well after a lot of needless panic, I put a bottle of Techron Fuel System Cleaner into the tank and let the truck sit overnight. I continued to drive the truck to work this week and the gauged started to move down from FULL. After a few days of driving, at the end of the week, I ended up at 1/4 full so the gauge was working again. I must have overfilled the tank last week when I filled up. Sometimes I do the extra "squeeze" on the pump trigger to get as much gas as I can into my tanks. I've leaned my lesson now. No more topping the tank off to the top of the filler neck.

Thankfully, it wasn't the slosh module, the cluster, the pump, the sending unit, wiring or any of the other endless possibilities that was causing me to panic.

Thank you everyone for your help and advise.

 

[sgtsandman]

Yep, only maybe one more squeeze after the first shut off of the nozzle. Contaminating your charcoal canister is another hazard you can run into if you over fill the fuel tank.

 

[MacCookie]

I'm new to the site/forum so my "handle" will not be familiar. It's also why I'm entering a little late on this topic. I bought a '99 XLT 4x4 auto in October 2018. Late last winter I had a similar issue with the fuel gauge - pinned to Full. It happened when the temperature dipped way down - below 15. In a couple of days and a bottle of STP fuel system cleaner, it worked normally. Then on Valentine's Day this month, it had been 13 degrees overnight and I took my Ranger to go get flowers. Hadn't driven it fo a few weeks, having been sick, so when I saw the "F"ull fuel gauge, I just assumed I had filled it my last few time out. Engine died on Interstate 78 and AAA took me to the nearest gas station. Again, 2-3 days later, gauge was working. Should I sauce the tank with more fuel cleaner or pull the pump assembly to see if I should replace it? Appreciate any other insights as to why the cold would impact the gauge sensor.

 

[acsnowrider]

Ford had a TSB, out for many years to add the Techron, prior to replacing in tank sender units! Don't remember what years it covered, but I was using it all through the early 2000 models. Ford paid for it.

 

[MacCookie]

Thanks so much. Will give the Techron a shot.

 

[acsnowrider]

Thanks so much. Will give the Techron a shot.

Replaced the Fuel Pump Module, in the tank on my 2004, at roughly 125000 miles, trying to pre-empt the loss of the original/failure leaving one on the side of the road---Put in a AIRTEX assy, and six months later, the sender unit started acting up--Cured the issue with Techron, but had to reapply/add it every 4-6 months again, after first use--Ford originally stated it was the "sulfur" in the fuel causing issue--Don't know if this is the real cause, but the Techron worked!